Bug 1393515 - Create mixin to show which props should be added to shouldComponentUpdate() r?jlast draft
authorMichael Ratcliffe <mratcliffe@mozilla.com>
Wed, 13 Sep 2017 15:54:32 +0100
changeset 664038 7a7c578c5b937f95ece33ab11b6fbba780a1f04a
parent 664035 4a7c9effe252e66a3544c654318cbb21340b60b6
child 731353 158778edb0e54252bcbc80bde55b910bf4fa5233
push id79602
push userbmo:mratcliffe@mozilla.com
push dateWed, 13 Sep 2017 17:06:13 +0000
reviewersjlast
bugs1393515
milestone57.0a1
Bug 1393515 - Create mixin to show which props should be added to shouldComponentUpdate() r?jlast I know the formatting of the output is not formatted perfectly but it is the best we can do for now. I will post a follow-up bug to fix it. You don't really need to review the library so you should focus on: - devtools/client/shared/vendor/jsondiffpatch/UPDATING.md - Just a markdown document. - devtools/shared/mixinService.js - Added jsondiffpatch - Renamed mixin methods to make them unique e.g. deepDiff_WhyDidYouUpdate... without this the mixins will not load. - toolkit/content/license.html - Added the google-diff-match-patch license. - Added the jsondiffpatch license. MozReview-Commit-ID: 5ejxCO5BO4h
devtools/client/shared/vendor/jsondiffpatch/UPDATING.md
devtools/client/shared/vendor/jsondiffpatch/formatter-json.js
devtools/client/shared/vendor/jsondiffpatch/formatters.js
devtools/client/shared/vendor/jsondiffpatch/jsondiffpatch-full.js
devtools/client/shared/vendor/jsondiffpatch/moz.build
devtools/client/shared/vendor/moz.build
devtools/shared/mixinService.js
modules/libpref/init/all.js
toolkit/content/license.html
new file mode 100644
--- /dev/null
+++ b/devtools/client/shared/vendor/jsondiffpatch/UPDATING.md
@@ -0,0 +1,49 @@
+# Updating this library
+
+1. Replace the contents of jsondiffpatch-full.js with the contents of
+   <https://github.com/keithnorm/jsondiffpatch/blob/master/public/build/jsondiffpatch-full.js>.
+
+2. Replace the contents of formatters.js with the contents of
+   <https://github.com/keithnorm/jsondiffpatch/blob/master/public/build/jsondiffpatch-formatters.js>.
+
+3. Find this section in jsondiffpatch-full.js:
+
+   ```
+    if (environment.isBrowser) {
+      exports.homepage = 'https://github.com/benjamine/jsondiffpatch';
+      exports.version = '0.2.4';
+    } else {
+      var packageInfoModuleName = '../package.json';
+      var packageInfo = require(packageInfoModuleName);
+      exports.homepage = packageInfo.homepage;
+      exports.version = packageInfo.version;
+
+      var formatterModuleName = './formatters';
+      var formatters = require(formatterModuleName);
+      exports.formatters = formatters;
+      // shortcut for console
+      exports.console = formatters.console;
+    }
+   ```
+
+   We cannot import package.json this way so we need to replace this block with:
+
+   ```
+   exports.homepage = 'https://github.com/benjamine/jsondiffpatch';
+   exports.version = '0.2.4';
+
+   var formatterModuleName = './formatters';
+   var formatters = require(formatterModuleName);
+   exports.formatters = formatters;
+   ```
+
+   NOTE: Use the relevant version number.
+
+4. Delete this section in formatters.js:
+
+   ```
+   if (!environment.isBrowser) {
+     var consoleModuleName = './console';
+     exports.console = require(consoleModuleName);
+   }
+   ```
new file mode 100644
--- /dev/null
+++ b/devtools/client/shared/vendor/jsondiffpatch/formatter-json.js
@@ -0,0 +1,168 @@
+var jsondiffpatch = require('./jsondiffpatch-full');
+var base = jsondiffpatch.formatters.base;
+var BaseFormatter = base.BaseFormatter;
+
+var AnnotatedFormatter = function AnnotatedFormatter() {
+  this.includeMoveDestinations = false;
+};
+
+AnnotatedFormatter.prototype = new BaseFormatter();
+
+AnnotatedFormatter.prototype.prepareContext = function(context) {
+  BaseFormatter.prototype.prepareContext.call(this, context);
+
+  context.indent = function(levels) {
+    this.indentLevel = (this.indentLevel || 0) +
+      (typeof levels === 'undefined' ? 1 : levels);
+    this.indentPad = new Array(this.indentLevel + 1).join('  ');
+  };
+  context.row = function(json, htmlNote) {
+    context.out(context.indentPad);
+    context.out(json);
+    context.out(context.indentPad);
+    context.out(htmlNote);
+  };
+};
+
+AnnotatedFormatter.prototype.typeFormattterErrorFormatter = function(context, err) {
+  context.row('', err);
+};
+
+AnnotatedFormatter.prototype.formatTextDiffString = function(context, value) {
+  var lines = this.parseTextDiff(value);
+
+  for (var i = 0, l = lines.length; i < l; i++) {
+    var line = lines[i];
+    context.out(line.location.line + ':' + line.location.chr);
+    var pieces = line.pieces;
+    for (var pieceIndex = 0, piecesLength = pieces.length; pieceIndex < piecesLength; pieceIndex++) {
+      var piece = pieces[pieceIndex];
+      context.out(piece.text);
+    }
+  }
+};
+
+AnnotatedFormatter.prototype.rootBegin = function(context, type, nodeType) {
+  if (type === 'node') {
+    context.row('{\n');
+    context.indent();
+  }
+};
+
+AnnotatedFormatter.prototype.rootEnd = function(context, type) {
+  if (type === 'node') {
+    context.indent(-1);
+    context.row('}\n');
+  }
+};
+
+AnnotatedFormatter.prototype.nodeBegin = function(context, key, leftKey, type, nodeType) {
+  context.row(`${key}: {\n`);
+  if (type === 'node') {
+    context.indent();
+  }
+};
+
+AnnotatedFormatter.prototype.nodeEnd = function(context, key, leftKey, type, nodeType, isLast) {
+  if (type === 'node') {
+    context.indent(-1);
+  }
+  context.row('}' + (isLast ? '' : ',') + '\n');
+};
+
+/* jshint camelcase: false */
+
+AnnotatedFormatter.prototype.format_unchanged = function() {
+  return;
+};
+
+AnnotatedFormatter.prototype.format_movedestination = function() {
+  return;
+};
+
+
+AnnotatedFormatter.prototype.format_node = function(context, delta, left) {
+  // recurse
+  this.formatDeltaChildren(context, delta, left);
+};
+
+var wrapPropertyName = function(name) {
+  return `"${name}"`;
+};
+
+var deltaAnnotations = {
+  added: function(delta, left, key, leftKey) {
+    if (typeof leftKey === 'undefined') {
+      return `\nCHANGE: new value ${delta[0]}\n`;
+    }
+    if (typeof leftKey === 'number') {
+      return `\nCHANGE: ${delta[0]} inserted at index ${leftKey}\n`;
+    }
+    return `\nCHANGE: added property ${wrapPropertyName(leftKey)}\n`;
+  },
+  modified: function(delta, left, key, leftKey) {
+    if (typeof leftKey === 'undefined') {
+      return `\nCHANGE: value ${delta[0]} changed to ${delta[1]}\n`;
+    }
+    if (typeof leftKey === 'number') {
+      return `\nCHANGE: ${delta[0]} modified at index ${leftKey}\n`;
+    }
+    return `\nCHANGE: modified property ${wrapPropertyName(leftKey)}\n`;
+  },
+  deleted: function(delta, left, key, leftKey) {
+    if (typeof leftKey === 'undefined') {
+      return `\nCHANGE: value ${delta[0]} deleted\n`;
+    }
+    if (typeof leftKey === 'number') {
+      return `\nCHANGE: ${delta[0]} removed at index ${leftKey}\n`;
+    }
+    return `\nCHANGE: deleted property ${wrapPropertyName(leftKey)}\n`;
+  },
+  moved: function(delta, left, key, leftKey) {
+    return `\nCHANGE: moved from index ${leftKey} to ${delta[1]}\n`;
+  },
+  textdiff: function(delta, left, key, leftKey) {
+    var location = (typeof leftKey === 'undefined') ?
+      '' : (
+        (typeof leftKey === 'number') ?
+        ` at index ${leftKey}` :
+        ` at property ${wrapPropertyName(leftKey)}`
+      );
+    return `\nCHANGE: text diff ${location}, format is ` +
+      'https://code.google.com/p/google-diff-match-patch/wiki/Unidiff' +
+      'a variation of Unidiff\n';
+  }
+};
+
+var formatAnyChange = function(context, delta) {
+  var deltaType = this.getDeltaType(delta);
+  var annotator = deltaAnnotations[deltaType];
+  var htmlNote = annotator && annotator.apply(annotator,
+    Array.prototype.slice.call(arguments, 1));
+  var json = JSON.stringify(delta, null, 2);
+
+  if (deltaType === 'textdiff') {
+    // split text diffs lines
+    json = json.split('\\n').join('\\n"+\n   "');
+  }
+  context.indent();
+  context.row(json, htmlNote);
+  context.indent(-1);
+};
+
+AnnotatedFormatter.prototype.format_added = formatAnyChange;
+AnnotatedFormatter.prototype.format_modified = formatAnyChange;
+AnnotatedFormatter.prototype.format_deleted = formatAnyChange;
+AnnotatedFormatter.prototype.format_moved = formatAnyChange;
+AnnotatedFormatter.prototype.format_textdiff = formatAnyChange;
+
+exports.AnnotatedFormatter = AnnotatedFormatter;
+
+var defaultInstance;
+
+exports.format = function(delta, left) {
+  if (!defaultInstance) {
+    defaultInstance = new AnnotatedFormatter();
+  }
+  return defaultInstance.format(delta, left);
+};
new file mode 100644
--- /dev/null
+++ b/devtools/client/shared/vendor/jsondiffpatch/formatters.js
@@ -0,0 +1,915 @@
+!function(e){if("object"==typeof exports&&"undefined"!=typeof module)module.exports=e();else if("function"==typeof define&&define.amd)define([],e);else{var f;"undefined"!=typeof window?f=window:"undefined"!=typeof global?f=global:"undefined"!=typeof self&&(f=self),(f.jsondiffpatch||(f.jsondiffpatch={})).formatters=e()}}(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
+
+  module.exports = require('./formatters');
+
+  },{"./formatters":6}],2:[function(require,module,exports){
+
+  exports.isBrowser = typeof window !== 'undefined';
+
+  },{}],3:[function(require,module,exports){
+  var base = require('./base');
+  var BaseFormatter = base.BaseFormatter;
+
+  var AnnotatedFormatter = function AnnotatedFormatter() {
+    this.includeMoveDestinations = false;
+  };
+
+  AnnotatedFormatter.prototype = new BaseFormatter();
+
+  AnnotatedFormatter.prototype.prepareContext = function(context) {
+    BaseFormatter.prototype.prepareContext.call(this, context);
+    context.indent = function(levels) {
+      this.indentLevel = (this.indentLevel || 0) +
+        (typeof levels === 'undefined' ? 1 : levels);
+      this.indentPad = new Array(this.indentLevel + 1).join('&nbsp;&nbsp;');
+    };
+    context.row = function(json, htmlNote) {
+      context.out('<tr><td style="white-space: nowrap;">' +
+        '<pre class="jsondiffpatch-annotated-indent" style="display: inline-block">');
+      context.out(context.indentPad);
+      context.out('</pre><pre style="display: inline-block">');
+      context.out(json);
+      context.out('</pre></td><td class="jsondiffpatch-delta-note"><div>');
+      context.out(htmlNote);
+      context.out('</div></td></tr>');
+    };
+  };
+
+  AnnotatedFormatter.prototype.typeFormattterErrorFormatter = function(context, err) {
+    context.row('', '<pre class="jsondiffpatch-error">' + err + '</pre>');
+  };
+
+  AnnotatedFormatter.prototype.formatTextDiffString = function(context, value) {
+    var lines = this.parseTextDiff(value);
+    context.out('<ul class="jsondiffpatch-textdiff">');
+    for (var i = 0, l = lines.length; i < l; i++) {
+      var line = lines[i];
+      context.out('<li>' +
+        '<div class="jsondiffpatch-textdiff-location">' +
+        '<span class="jsondiffpatch-textdiff-line-number">' +
+        line.location.line +
+        '</span>' +
+        '<span class="jsondiffpatch-textdiff-char">' +
+        line.location.chr +
+        '</span>' +
+        '</div>' +
+        '<div class="jsondiffpatch-textdiff-line">');
+      var pieces = line.pieces;
+      for (var pieceIndex = 0, piecesLength = pieces.length; pieceIndex < piecesLength; pieceIndex++) {
+        var piece = pieces[pieceIndex];
+        context.out('<span class="jsondiffpatch-textdiff-' + piece.type + '">' +
+          piece.text + '</span>');
+      }
+      context.out('</div></li>');
+    }
+    context.out('</ul>');
+  };
+
+  AnnotatedFormatter.prototype.rootBegin = function(context, type, nodeType) {
+    context.out('<table class="jsondiffpatch-annotated-delta">');
+    if (type === 'node') {
+      context.row('{');
+      context.indent();
+    }
+    if (nodeType === 'array') {
+      context.row('"_t": "a",', 'Array delta (member names indicate array indices)');
+    }
+  };
+
+  AnnotatedFormatter.prototype.rootEnd = function(context, type) {
+    if (type === 'node') {
+      context.indent(-1);
+      context.row('}');
+    }
+    context.out('</table>');
+  };
+
+  AnnotatedFormatter.prototype.nodeBegin = function(context, key, leftKey, type, nodeType) {
+    context.row('&quot;' + key + '&quot;: {');
+    if (type === 'node') {
+      context.indent();
+    }
+    if (nodeType === 'array') {
+      context.row('"_t": "a",', 'Array delta (member names indicate array indices)');
+    }
+  };
+
+  AnnotatedFormatter.prototype.nodeEnd = function(context, key, leftKey, type, nodeType, isLast) {
+    if (type === 'node') {
+      context.indent(-1);
+    }
+    context.row('}' + (isLast ? '' : ','));
+  };
+
+  /* jshint camelcase: false */
+
+  AnnotatedFormatter.prototype.format_unchanged = function() {
+    return;
+  };
+
+  AnnotatedFormatter.prototype.format_movedestination = function() {
+    return;
+  };
+
+
+  AnnotatedFormatter.prototype.format_node = function(context, delta, left) {
+    // recurse
+    this.formatDeltaChildren(context, delta, left);
+  };
+
+  var wrapPropertyName = function(name) {
+    return '<pre style="display:inline-block">&quot;' + name + '&quot;</pre>';
+  };
+
+  var deltaAnnotations = {
+    added: function(delta, left, key, leftKey) {
+      var formatLegend = ' <pre>([newValue])</pre>';
+      if (typeof leftKey === 'undefined') {
+        return 'new value' + formatLegend;
+      }
+      if (typeof leftKey === 'number') {
+        return 'insert at index ' + leftKey + formatLegend;
+      }
+      return 'add property ' + wrapPropertyName(leftKey) + formatLegend;
+    },
+    modified: function(delta, left, key, leftKey) {
+      var formatLegend = ' <pre>([previousValue, newValue])</pre>';
+      if (typeof leftKey === 'undefined') {
+        return 'modify value' + formatLegend;
+      }
+      if (typeof leftKey === 'number') {
+        return 'modify at index ' + leftKey + formatLegend;
+      }
+      return 'modify property ' + wrapPropertyName(leftKey) + formatLegend;
+    },
+    deleted: function(delta, left, key, leftKey) {
+      var formatLegend = ' <pre>([previousValue, 0, 0])</pre>';
+      if (typeof leftKey === 'undefined') {
+        return 'delete value' + formatLegend;
+      }
+      if (typeof leftKey === 'number') {
+        return 'remove index ' + leftKey + formatLegend;
+      }
+      return 'delete property ' + wrapPropertyName(leftKey) + formatLegend;
+    },
+    moved: function(delta, left, key, leftKey) {
+      return 'move from <span title="(position to remove at original state)">index ' +
+        leftKey + '</span> to ' +
+        '<span title="(position to insert at final state)">index ' +
+        delta[1] + '</span>';
+    },
+    textdiff: function(delta, left, key, leftKey) {
+      var location = (typeof leftKey === 'undefined') ?
+        '' : (
+          (typeof leftKey === 'number') ?
+          ' at index ' + leftKey :
+          ' at property ' + wrapPropertyName(leftKey)
+        );
+      return 'text diff' + location + ', format is ' +
+        '<a href="https://code.google.com/p/google-diff-match-patch/wiki/Unidiff">' +
+        'a variation of Unidiff</a>';
+    }
+  };
+
+  var formatAnyChange = function(context, delta) {
+    var deltaType = this.getDeltaType(delta);
+    var annotator = deltaAnnotations[deltaType];
+    var htmlNote = annotator && annotator.apply(annotator,
+      Array.prototype.slice.call(arguments, 1));
+    var json = JSON.stringify(delta, null, 2);
+    if (deltaType === 'textdiff') {
+      // split text diffs lines
+      json = json.split('\\n').join('\\n"+\n   "');
+    }
+    context.indent();
+    context.row(json, htmlNote);
+    context.indent(-1);
+  };
+
+  AnnotatedFormatter.prototype.format_added = formatAnyChange;
+  AnnotatedFormatter.prototype.format_modified = formatAnyChange;
+  AnnotatedFormatter.prototype.format_deleted = formatAnyChange;
+  AnnotatedFormatter.prototype.format_moved = formatAnyChange;
+  AnnotatedFormatter.prototype.format_textdiff = formatAnyChange;
+
+  /* jshint camelcase: true */
+
+  exports.AnnotatedFormatter = AnnotatedFormatter;
+
+  var defaultInstance;
+
+  exports.format = function(delta, left) {
+    if (!defaultInstance) {
+      defaultInstance = new AnnotatedFormatter();
+    }
+    return defaultInstance.format(delta, left);
+  };
+
+  },{"./base":4}],4:[function(require,module,exports){
+  var isArray = (typeof Array.isArray === 'function') ?
+    // use native function
+    Array.isArray :
+    // use instanceof operator
+    function(a) {
+      return a instanceof Array;
+    };
+
+  var getObjectKeys = typeof Object.keys === 'function' ?
+    function(obj) {
+      return Object.keys(obj);
+    } : function(obj) {
+      var names = [];
+      for (var property in obj) {
+        if (Object.prototype.hasOwnProperty.call(obj, property)) {
+          names.push(property);
+        }
+      }
+      return names;
+    };
+
+  var trimUnderscore = function(str) {
+    if (str.substr(0, 1) === '_') {
+      return str.slice(1);
+    }
+    return str;
+  };
+
+  var arrayKeyToSortNumber = function(key) {
+    if (key === '_t') {
+      return -1;
+    } else {
+      if (key.substr(0, 1) === '_') {
+        return parseInt(key.slice(1), 10);
+      } else {
+        return parseInt(key, 10) + 0.1;
+      }
+    }
+  };
+
+  var arrayKeyComparer = function(key1, key2) {
+    return arrayKeyToSortNumber(key1) - arrayKeyToSortNumber(key2);
+  };
+
+  var BaseFormatter = function BaseFormatter() {};
+
+  BaseFormatter.prototype.format = function(delta, left) {
+    var context = {};
+    this.prepareContext(context);
+    this.recurse(context, delta, left);
+    return this.finalize(context);
+  };
+
+  BaseFormatter.prototype.prepareContext = function(context) {
+    context.buffer = [];
+    context.out = function() {
+      this.buffer.push.apply(this.buffer, arguments);
+    };
+  };
+
+  BaseFormatter.prototype.typeFormattterNotFound = function(context, deltaType) {
+    throw new Error('cannot format delta type: ' + deltaType);
+  };
+
+  BaseFormatter.prototype.typeFormattterErrorFormatter = function(context, err) {
+    return err.toString();
+  };
+
+  BaseFormatter.prototype.finalize = function(context) {
+    if (isArray(context.buffer)) {
+      return context.buffer.join('');
+    }
+  };
+
+  BaseFormatter.prototype.recurse = function(context, delta, left, key, leftKey, movedFrom, isLast) {
+
+    var useMoveOriginHere = delta && movedFrom;
+    var leftValue = useMoveOriginHere ? movedFrom.value : left;
+
+    if (typeof delta === 'undefined' && typeof key === 'undefined') {
+      return undefined;
+    }
+
+    var type = this.getDeltaType(delta, movedFrom);
+    var nodeType = type === 'node' ? (delta._t === 'a' ? 'array' : 'object') : '';
+
+    if (typeof key !== 'undefined') {
+      this.nodeBegin(context, key, leftKey, type, nodeType, isLast);
+    } else {
+      this.rootBegin(context, type, nodeType);
+    }
+
+    var typeFormattter;
+    try {
+      typeFormattter = this['format_' + type] || this.typeFormattterNotFound(context, type);
+      typeFormattter.call(this, context, delta, leftValue, key, leftKey, movedFrom);
+    } catch (err) {
+      this.typeFormattterErrorFormatter(context, err, delta, leftValue, key, leftKey, movedFrom);
+      if (typeof console !== 'undefined' && console.error) {
+        console.error(err.stack);
+      }
+    }
+
+    if (typeof key !== 'undefined') {
+      this.nodeEnd(context, key, leftKey, type, nodeType, isLast);
+    } else {
+      this.rootEnd(context, type, nodeType);
+    }
+  };
+
+  BaseFormatter.prototype.formatDeltaChildren = function(context, delta, left) {
+    var self = this;
+    this.forEachDeltaKey(delta, left, function(key, leftKey, movedFrom, isLast) {
+      self.recurse(context, delta[key], left ? left[leftKey] : undefined,
+        key, leftKey, movedFrom, isLast);
+    });
+  };
+
+  BaseFormatter.prototype.forEachDeltaKey = function(delta, left, fn) {
+    var keys = getObjectKeys(delta);
+    var arrayKeys = delta._t === 'a';
+    var moveDestinations = {};
+    var name;
+    if (typeof left !== 'undefined') {
+      for (name in left) {
+        if (Object.prototype.hasOwnProperty.call(left, name)) {
+          if (typeof delta[name] === 'undefined' &&
+            ((!arrayKeys) || typeof delta['_' + name] === 'undefined')) {
+            keys.push(name);
+          }
+        }
+      }
+    }
+    // look for move destinations
+    for (name in delta) {
+      if (Object.prototype.hasOwnProperty.call(delta, name)) {
+        var value = delta[name];
+        if (isArray(value) && value[2] === 3) {
+          moveDestinations[value[1].toString()] = {
+            key: name,
+            value: left && left[parseInt(name.substr(1))]
+          };
+          if (this.includeMoveDestinations !== false) {
+            if ((typeof left === 'undefined') &&
+              (typeof delta[value[1]] === 'undefined')) {
+              keys.push(value[1].toString());
+            }
+          }
+        }
+      }
+    }
+    if (arrayKeys) {
+      keys.sort(arrayKeyComparer);
+    } else {
+      keys.sort();
+    }
+    for (var index = 0, length = keys.length; index < length; index++) {
+      var key = keys[index];
+      if (arrayKeys && key === '_t') {
+        continue;
+      }
+      var leftKey = arrayKeys ?
+        (typeof key === 'number' ? key : parseInt(trimUnderscore(key), 10)) :
+        key;
+      var isLast = (index === length - 1);
+      fn(key, leftKey, moveDestinations[leftKey], isLast);
+    }
+  };
+
+  BaseFormatter.prototype.getDeltaType = function(delta, movedFrom) {
+    if (typeof delta === 'undefined') {
+      if (typeof movedFrom !== 'undefined') {
+        return 'movedestination';
+      }
+      return 'unchanged';
+    }
+    if (isArray(delta)) {
+      if (delta.length === 1) {
+        return 'added';
+      }
+      if (delta.length === 2) {
+        return 'modified';
+      }
+      if (delta.length === 3 && delta[2] === 0) {
+        return 'deleted';
+      }
+      if (delta.length === 3 && delta[2] === 2) {
+        return 'textdiff';
+      }
+      if (delta.length === 3 && delta[2] === 3) {
+        return 'moved';
+      }
+    } else if (typeof delta === 'object') {
+      return 'node';
+    }
+    return 'unknown';
+  };
+
+  BaseFormatter.prototype.parseTextDiff = function(value) {
+    var output = [];
+    var lines = value.split('\n@@ ');
+    for (var i = 0, l = lines.length; i < l; i++) {
+      var line = lines[i];
+      var lineOutput = {
+        pieces: []
+      };
+      var location = /^(?:@@ )?[-+]?(\d+),(\d+)/.exec(line).slice(1);
+      lineOutput.location = {
+        line: location[0],
+        chr: location[1]
+      };
+      var pieces = line.split('\n').slice(1);
+      for (var pieceIndex = 0, piecesLength = pieces.length; pieceIndex < piecesLength; pieceIndex++) {
+        var piece = pieces[pieceIndex];
+        if (!piece.length) {
+          continue;
+        }
+        var pieceOutput = {
+          type: 'context'
+        };
+        if (piece.substr(0, 1) === '+') {
+          pieceOutput.type = 'added';
+        } else if (piece.substr(0, 1) === '-') {
+          pieceOutput.type = 'deleted';
+        }
+        pieceOutput.text = piece.slice(1);
+        lineOutput.pieces.push(pieceOutput);
+      }
+      output.push(lineOutput);
+    }
+    return output;
+  };
+
+  exports.BaseFormatter = BaseFormatter;
+
+  },{}],5:[function(require,module,exports){
+  var base = require('./base');
+  var BaseFormatter = base.BaseFormatter;
+
+  var HtmlFormatter = function HtmlFormatter() {};
+
+  HtmlFormatter.prototype = new BaseFormatter();
+
+  function htmlEscape(text) {
+    var html = text;
+    var replacements = [
+      [/&/g, '&amp;'],
+      [/</g, '&lt;'],
+      [/>/g, '&gt;'],
+      [/'/g, '&apos;'],
+      [/"/g, '&quot;']
+    ];
+    for (var i = 0; i < replacements.length; i++) {
+      html = html.replace(replacements[i][0], replacements[i][1]);
+    }
+    return html;
+  }
+
+  HtmlFormatter.prototype.typeFormattterErrorFormatter = function(context, err) {
+    context.out('<pre class="jsondiffpatch-error">' + err + '</pre>');
+  };
+
+  HtmlFormatter.prototype.formatValue = function(context, value) {
+    context.out('<pre>' + htmlEscape(JSON.stringify(value, null, 2)) + '</pre>');
+  };
+
+  HtmlFormatter.prototype.formatTextDiffString = function(context, value) {
+    var lines = this.parseTextDiff(value);
+    context.out('<ul class="jsondiffpatch-textdiff">');
+    for (var i = 0, l = lines.length; i < l; i++) {
+      var line = lines[i];
+      context.out('<li>' +
+        '<div class="jsondiffpatch-textdiff-location">' +
+        '<span class="jsondiffpatch-textdiff-line-number">' +
+        line.location.line +
+        '</span>' +
+        '<span class="jsondiffpatch-textdiff-char">' +
+        line.location.chr +
+        '</span>' +
+        '</div>' +
+        '<div class="jsondiffpatch-textdiff-line">');
+      var pieces = line.pieces;
+      for (var pieceIndex = 0, piecesLength = pieces.length; pieceIndex < piecesLength; pieceIndex++) {
+        /* global unescape */
+        var piece = pieces[pieceIndex];
+        context.out('<span class="jsondiffpatch-textdiff-' + piece.type + '">' +
+          htmlEscape(unescape(piece.text)) + '</span>');
+      }
+      context.out('</div></li>');
+    }
+    context.out('</ul>');
+  };
+
+  var adjustArrows = function jsondiffpatchHtmlFormatterAdjustArrows(node) {
+    node = node || document;
+    var getElementText = function(el) {
+      return el.textContent || el.innerText;
+    };
+    var eachByQuery = function(el, query, fn) {
+      var elems = el.querySelectorAll(query);
+      for (var i = 0, l = elems.length; i < l; i++) {
+        fn(elems[i]);
+      }
+    };
+    var eachChildren = function(el, fn) {
+      for (var i = 0, l = el.children.length; i < l; i++) {
+        fn(el.children[i], i);
+      }
+    };
+    eachByQuery(node, '.jsondiffpatch-arrow', function(arrow) {
+      var arrowParent = arrow.parentNode;
+      var svg = arrow.children[0],
+        path = svg.children[1];
+      svg.style.display = 'none';
+      var destination = getElementText(arrowParent.querySelector('.jsondiffpatch-moved-destination'));
+      var container = arrowParent.parentNode;
+      var destinationElem;
+      eachChildren(container, function(child) {
+        if (child.getAttribute('data-key') === destination) {
+          destinationElem = child;
+        }
+      });
+      if (!destinationElem) {
+        return;
+      }
+      try {
+        var distance = destinationElem.offsetTop - arrowParent.offsetTop;
+        svg.setAttribute('height', Math.abs(distance) + 6);
+        arrow.style.top = (-8 + (distance > 0 ? 0 : distance)) + 'px';
+        var curve = distance > 0 ?
+          'M30,0 Q-10,' + Math.round(distance / 2) + ' 26,' + (distance - 4) :
+          'M30,' + (-distance) + ' Q-10,' + Math.round(-distance / 2) + ' 26,4';
+        path.setAttribute('d', curve);
+        svg.style.display = '';
+      } catch (err) {
+        return;
+      }
+    });
+  };
+
+  HtmlFormatter.prototype.rootBegin = function(context, type, nodeType) {
+    var nodeClass = 'jsondiffpatch-' + type +
+      (nodeType ? ' jsondiffpatch-child-node-type-' + nodeType : '');
+    context.out('<div class="jsondiffpatch-delta ' + nodeClass + '">');
+  };
+
+  HtmlFormatter.prototype.rootEnd = function(context) {
+    context.out('</div>' + (context.hasArrows ?
+      ('<script type="text/javascript">setTimeout(' +
+        adjustArrows.toString() +
+        ',10);</script>') : ''));
+  };
+
+  HtmlFormatter.prototype.nodeBegin = function(context, key, leftKey, type, nodeType) {
+    var nodeClass = 'jsondiffpatch-' + type +
+      (nodeType ? ' jsondiffpatch-child-node-type-' + nodeType : '');
+    context.out('<li class="' + nodeClass + '" data-key="' + leftKey + '">' +
+      '<div class="jsondiffpatch-property-name">' + leftKey + '</div>');
+  };
+
+
+  HtmlFormatter.prototype.nodeEnd = function(context) {
+    context.out('</li>');
+  };
+
+  /* jshint camelcase: false */
+
+  HtmlFormatter.prototype.format_unchanged = function(context, delta, left) {
+    if (typeof left === 'undefined') {
+      return;
+    }
+    context.out('<div class="jsondiffpatch-value">');
+    this.formatValue(context, left);
+    context.out('</div>');
+  };
+
+  HtmlFormatter.prototype.format_movedestination = function(context, delta, left) {
+    if (typeof left === 'undefined') {
+      return;
+    }
+    context.out('<div class="jsondiffpatch-value">');
+    this.formatValue(context, left);
+    context.out('</div>');
+  };
+
+  HtmlFormatter.prototype.format_node = function(context, delta, left) {
+    // recurse
+    var nodeType = (delta._t === 'a') ? 'array' : 'object';
+    context.out('<ul class="jsondiffpatch-node jsondiffpatch-node-type-' + nodeType + '">');
+    this.formatDeltaChildren(context, delta, left);
+    context.out('</ul>');
+  };
+
+  HtmlFormatter.prototype.format_added = function(context, delta) {
+    context.out('<div class="jsondiffpatch-value">');
+    this.formatValue(context, delta[0]);
+    context.out('</div>');
+  };
+
+  HtmlFormatter.prototype.format_modified = function(context, delta) {
+    context.out('<div class="jsondiffpatch-value jsondiffpatch-left-value">');
+    this.formatValue(context, delta[0]);
+    context.out('</div>' +
+      '<div class="jsondiffpatch-value jsondiffpatch-right-value">');
+    this.formatValue(context, delta[1]);
+    context.out('</div>');
+  };
+
+  HtmlFormatter.prototype.format_deleted = function(context, delta) {
+    context.out('<div class="jsondiffpatch-value">');
+    this.formatValue(context, delta[0]);
+    context.out('</div>');
+  };
+
+  HtmlFormatter.prototype.format_moved = function(context, delta) {
+    context.out('<div class="jsondiffpatch-value">');
+    this.formatValue(context, delta[0]);
+    context.out('</div><div class="jsondiffpatch-moved-destination">' + delta[1] + '</div>');
+
+    // draw an SVG arrow from here to move destination
+    context.out(
+      /*jshint multistr: true */
+      '<div class="jsondiffpatch-arrow" style="position: relative; left: -34px;">\
+          <svg width="30" height="60" style="position: absolute; display: none;">\
+          <defs>\
+              <marker id="markerArrow" markerWidth="8" markerHeight="8" refx="2" refy="4"\
+                     orient="auto" markerUnits="userSpaceOnUse">\
+                  <path d="M1,1 L1,7 L7,4 L1,1" style="fill: #339;" />\
+              </marker>\
+          </defs>\
+          <path d="M30,0 Q-10,25 26,50" style="stroke: #88f; stroke-width: 2px; fill: none;\
+          stroke-opacity: 0.5; marker-end: url(#markerArrow);"></path>\
+          </svg>\
+          </div>');
+    context.hasArrows = true;
+  };
+
+  HtmlFormatter.prototype.format_textdiff = function(context, delta) {
+    context.out('<div class="jsondiffpatch-value">');
+    this.formatTextDiffString(context, delta[0]);
+    context.out('</div>');
+  };
+
+  /* jshint camelcase: true */
+
+  var showUnchanged = function(show, node, delay) {
+    var el = node || document.body;
+    var prefix = 'jsondiffpatch-unchanged-';
+    var classes = {
+      showing: prefix + 'showing',
+      hiding: prefix + 'hiding',
+      visible: prefix + 'visible',
+      hidden: prefix + 'hidden',
+    };
+    var list = el.classList;
+    if (!list) {
+      return;
+    }
+    if (!delay) {
+      list.remove(classes.showing);
+      list.remove(classes.hiding);
+      list.remove(classes.visible);
+      list.remove(classes.hidden);
+      if (show === false) {
+        list.add(classes.hidden);
+      }
+      return;
+    }
+    if (show === false) {
+      list.remove(classes.showing);
+      list.add(classes.visible);
+      setTimeout(function() {
+        list.add(classes.hiding);
+      }, 10);
+    } else {
+      list.remove(classes.hiding);
+      list.add(classes.showing);
+      list.remove(classes.hidden);
+    }
+    var intervalId = setInterval(function() {
+      adjustArrows(el);
+    }, 100);
+    setTimeout(function() {
+      list.remove(classes.showing);
+      list.remove(classes.hiding);
+      if (show === false) {
+        list.add(classes.hidden);
+        list.remove(classes.visible);
+      } else {
+        list.add(classes.visible);
+        list.remove(classes.hidden);
+      }
+      setTimeout(function() {
+        list.remove(classes.visible);
+        clearInterval(intervalId);
+      }, delay + 400);
+    }, delay);
+  };
+
+  var hideUnchanged = function(node, delay) {
+    return showUnchanged(false, node, delay);
+  };
+
+  exports.HtmlFormatter = HtmlFormatter;
+
+  exports.showUnchanged = showUnchanged;
+
+  exports.hideUnchanged = hideUnchanged;
+
+  var defaultInstance;
+
+  exports.format = function(delta, left) {
+    if (!defaultInstance) {
+      defaultInstance = new HtmlFormatter();
+    }
+    return defaultInstance.format(delta, left);
+  };
+
+  },{"./base":4}],6:[function(require,module,exports){
+  var environment = require('../environment');
+
+  exports.base = require('./base');
+  exports.html = require('./html');
+  exports.annotated = require('./annotated');
+  exports.jsonpatch = require('./jsonpatch');
+  },{"../environment":2,"./annotated":3,"./base":4,"./html":5,"./jsonpatch":7}],7:[function(require,module,exports){
+  (function () {
+    var base = require('./base');
+    var BaseFormatter = base.BaseFormatter;
+
+    var named = {
+      added: 'add',
+      deleted: 'remove',
+      modified: 'replace',
+      moved: 'moved',
+      movedestination: 'movedestination',
+      unchanged: 'unchanged',
+      error: 'error',
+      textDiffLine: 'textDiffLine'
+    };
+
+    function JSONFormatter() {
+      this.includeMoveDestinations = false;
+    }
+
+    JSONFormatter.prototype = new BaseFormatter();
+
+    JSONFormatter.prototype.prepareContext = function (context) {
+      BaseFormatter.prototype.prepareContext.call(this, context);
+      context.result = [];
+      context.path = [];
+      context.pushCurrentOp = function (op, value) {
+        var val = {
+          op: op,
+          path: this.currentPath()
+        };
+        if (typeof value !== 'undefined') {
+          val.value = value;
+        }
+        this.result.push(val);
+      };
+
+      context.currentPath = function () {
+        return '/' + this.path.join('/');
+      };
+    };
+
+    JSONFormatter.prototype.typeFormattterErrorFormatter = function (context, err) {
+      context.out('[ERROR]' + err);
+    };
+
+    JSONFormatter.prototype.rootBegin = function () {
+    };
+
+    JSONFormatter.prototype.rootEnd = function () {
+    };
+
+    JSONFormatter.prototype.nodeBegin = function (context, key, leftKey) {
+      context.path.push(leftKey);
+    };
+
+    JSONFormatter.prototype.nodeEnd = function (context) {
+      context.path.pop();
+    };
+
+    /* jshint camelcase: false */
+
+    JSONFormatter.prototype.format_unchanged = function (context, delta, left) {
+      if (typeof left === 'undefined') {
+        return;
+      }
+      context.pushCurrentOp(named.unchanged, left);
+    };
+
+    JSONFormatter.prototype.format_movedestination = function (context, delta, left) {
+      if (typeof left === 'undefined') {
+        return;
+      }
+      context.pushCurrentOp(named.movedestination, left);
+    };
+
+    JSONFormatter.prototype.format_node = function (context, delta, left) {
+      this.formatDeltaChildren(context, delta, left);
+    };
+
+    JSONFormatter.prototype.format_added = function (context, delta) {
+      context.pushCurrentOp(named.added, delta[0]);
+    };
+
+    JSONFormatter.prototype.format_modified = function (context, delta) {
+      context.pushCurrentOp(named.modified, delta[1]);
+    };
+
+    JSONFormatter.prototype.format_deleted = function (context) {
+      context.pushCurrentOp(named.deleted);
+    };
+
+    JSONFormatter.prototype.format_moved = function (context, delta) {
+      context.pushCurrentOp(named.moved, delta[1]);
+    };
+
+    JSONFormatter.prototype.format_textdiff = function () {
+      throw 'not implimented';
+    };
+
+    JSONFormatter.prototype.format = function (delta, left) {
+      var context = {};
+      this.prepareContext(context);
+      this.recurse(context, delta, left);
+      return context.result;
+    };
+    /* jshint camelcase: true */
+
+    exports.JSONFormatter = JSONFormatter;
+
+    var defaultInstance;
+
+    function last(arr) {
+      return arr[arr.length - 1];
+    }
+
+    function sortBy(arr, pred) {
+      arr.sort(pred);
+      return arr;
+    }
+
+    var compareByIndexDesc = function (indexA, indexB) {
+      var lastA = parseInt(indexA, 10);
+      var lastB = parseInt(indexB, 10);
+      if (!(isNaN(lastA) || isNaN(lastB))) {
+        return lastB - lastA;
+      } else {
+        return 0;
+      }
+    };
+
+    function opsByDescendingOrder(removeOps) {
+      return sortBy(removeOps, function (a, b) {
+        var splitA = a.path.split('/');
+        var splitB = b.path.split('/');
+        if (splitA.length !== splitB.length) {
+          return splitA.length - splitB.length;
+        } else {
+          return compareByIndexDesc(last(splitA), last(splitB));
+        }
+      });
+    }
+
+    function partition(arr, pred) {
+      var left = [];
+      var right = [];
+
+      arr.forEach(function (el) {
+        var coll = pred(el) ? left : right;
+        coll.push(el);
+      });
+      return [left, right];
+    }
+
+    function reorderOps(jsonFormattedDiff) {
+      var removeOpsOtherOps = partition(jsonFormattedDiff, function (operation) {
+        return operation.op === 'remove';
+      });
+      var removeOps = removeOpsOtherOps[0];
+      var otherOps = removeOpsOtherOps[1];
+
+      var removeOpsReverse = opsByDescendingOrder(removeOps);
+      return removeOpsReverse.concat(otherOps);
+    }
+
+
+    var format = function (delta, left) {
+      if (!defaultInstance) {
+        defaultInstance = new JSONFormatter();
+      }
+      return reorderOps(defaultInstance.format(delta, left));
+    };
+
+    exports.log = function (delta, left) {
+      console.log(format(delta, left));
+    };
+
+    exports.format = format;
+  })();
+
+  },{"./base":4}]},{},[1])(1)
+  });
new file mode 100644
--- /dev/null
+++ b/devtools/client/shared/vendor/jsondiffpatch/jsondiffpatch-full.js
@@ -0,0 +1,3579 @@
+!function(e){if("object"==typeof exports&&"undefined"!=typeof module)module.exports=e();else if("function"==typeof define&&define.amd)define([],e);else{var f;"undefined"!=typeof window?f=window:"undefined"!=typeof global?f=global:"undefined"!=typeof self&&(f=self),f.jsondiffpatch=e()}}(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
+  var environment = require('./environment');
+
+  if (environment.isBrowser) {
+    /* global window */
+    /* jshint camelcase: false */
+    window.diff_match_patch = require('../public/external/diff_match_patch_uncompressed');
+    /* jshint camelcase: true */
+  }
+
+  module.exports = require('./main');
+
+  },{"../public/external/diff_match_patch_uncompressed":2,"./environment":10,"./main":17}],2:[function(require,module,exports){
+  /**
+   * Diff Match and Patch
+   *
+   * Copyright 2006 Google Inc.
+   * http://code.google.com/p/google-diff-match-patch/
+   *
+   * Licensed under the Apache License, Version 2.0 (the "License");
+   * you may not use this file except in compliance with the License.
+   * You may obtain a copy of the License at
+   *
+   *   http://www.apache.org/licenses/LICENSE-2.0
+   *
+   * Unless required by applicable law or agreed to in writing, software
+   * distributed under the License is distributed on an "AS IS" BASIS,
+   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   * See the License for the specific language governing permissions and
+   * limitations under the License.
+   */
+
+  /**
+   * @fileoverview Computes the difference between two texts to create a patch.
+   * Applies the patch onto another text, allowing for errors.
+   * @author fraser@google.com (Neil Fraser)
+   */
+
+  /**
+   * Class containing the diff, match and patch methods.
+   * @constructor
+   */
+  function diff_match_patch() {
+
+    // Defaults.
+    // Redefine these in your program to override the defaults.
+
+    // Number of seconds to map a diff before giving up (0 for infinity).
+    this.Diff_Timeout = 1.0;
+    // Cost of an empty edit operation in terms of edit characters.
+    this.Diff_EditCost = 4;
+    // At what point is no match declared (0.0 = perfection, 1.0 = very loose).
+    this.Match_Threshold = 0.5;
+    // How far to search for a match (0 = exact location, 1000+ = broad match).
+    // A match this many characters away from the expected location will add
+    // 1.0 to the score (0.0 is a perfect match).
+    this.Match_Distance = 1000;
+    // When deleting a large block of text (over ~64 characters), how close does
+    // the contents have to match the expected contents. (0.0 = perfection,
+    // 1.0 = very loose).  Note that Match_Threshold controls how closely the
+    // end points of a delete need to match.
+    this.Patch_DeleteThreshold = 0.5;
+    // Chunk size for context length.
+    this.Patch_Margin = 4;
+
+    // The number of bits in an int.
+    this.Match_MaxBits = 32;
+  }
+
+
+  //  DIFF FUNCTIONS
+
+
+  /**
+   * The data structure representing a diff is an array of tuples:
+   * [[DIFF_DELETE, 'Hello'], [DIFF_INSERT, 'Goodbye'], [DIFF_EQUAL, ' world.']]
+   * which means: delete 'Hello', add 'Goodbye' and keep ' world.'
+   */
+  var DIFF_DELETE = -1;
+  var DIFF_INSERT = 1;
+  var DIFF_EQUAL = 0;
+
+  /** @typedef {!Array.<number|string>} */
+  diff_match_patch.Diff;
+
+
+  /**
+   * Find the differences between two texts.  Simplifies the problem by stripping
+   * any common prefix or suffix off the texts before diffing.
+   * @param {string} text1 Old string to be diffed.
+   * @param {string} text2 New string to be diffed.
+   * @param {boolean=} opt_checklines Optional speedup flag. If present and false,
+   *     then don't run a line-level diff first to identify the changed areas.
+   *     Defaults to true, which does a faster, slightly less optimal diff.
+   * @param {number} opt_deadline Optional time when the diff should be complete
+   *     by.  Used internally for recursive calls.  Users should set DiffTimeout
+   *     instead.
+   * @return {!Array.<!diff_match_patch.Diff>} Array of diff tuples.
+   */
+  diff_match_patch.prototype.diff_main = function(text1, text2, opt_checklines,
+      opt_deadline) {
+    // Set a deadline by which time the diff must be complete.
+    if (typeof opt_deadline == 'undefined') {
+      if (this.Diff_Timeout <= 0) {
+        opt_deadline = Number.MAX_VALUE;
+      } else {
+        opt_deadline = (new Date).getTime() + this.Diff_Timeout * 1000;
+      }
+    }
+    var deadline = opt_deadline;
+
+    // Check for null inputs.
+    if (text1 == null || text2 == null) {
+      throw new Error('Null input. (diff_main)');
+    }
+
+    // Check for equality (speedup).
+    if (text1 == text2) {
+      if (text1) {
+        return [[DIFF_EQUAL, text1]];
+      }
+      return [];
+    }
+
+    if (typeof opt_checklines == 'undefined') {
+      opt_checklines = true;
+    }
+    var checklines = opt_checklines;
+
+    // Trim off common prefix (speedup).
+    var commonlength = this.diff_commonPrefix(text1, text2);
+    var commonprefix = text1.substring(0, commonlength);
+    text1 = text1.substring(commonlength);
+    text2 = text2.substring(commonlength);
+
+    // Trim off common suffix (speedup).
+    commonlength = this.diff_commonSuffix(text1, text2);
+    var commonsuffix = text1.substring(text1.length - commonlength);
+    text1 = text1.substring(0, text1.length - commonlength);
+    text2 = text2.substring(0, text2.length - commonlength);
+
+    // Compute the diff on the middle block.
+    var diffs = this.diff_compute_(text1, text2, checklines, deadline);
+
+    // Restore the prefix and suffix.
+    if (commonprefix) {
+      diffs.unshift([DIFF_EQUAL, commonprefix]);
+    }
+    if (commonsuffix) {
+      diffs.push([DIFF_EQUAL, commonsuffix]);
+    }
+    this.diff_cleanupMerge(diffs);
+    return diffs;
+  };
+
+
+  /**
+   * Find the differences between two texts.  Assumes that the texts do not
+   * have any common prefix or suffix.
+   * @param {string} text1 Old string to be diffed.
+   * @param {string} text2 New string to be diffed.
+   * @param {boolean} checklines Speedup flag.  If false, then don't run a
+   *     line-level diff first to identify the changed areas.
+   *     If true, then run a faster, slightly less optimal diff.
+   * @param {number} deadline Time when the diff should be complete by.
+   * @return {!Array.<!diff_match_patch.Diff>} Array of diff tuples.
+   * @private
+   */
+  diff_match_patch.prototype.diff_compute_ = function(text1, text2, checklines,
+      deadline) {
+    var diffs;
+
+    if (!text1) {
+      // Just add some text (speedup).
+      return [[DIFF_INSERT, text2]];
+    }
+
+    if (!text2) {
+      // Just delete some text (speedup).
+      return [[DIFF_DELETE, text1]];
+    }
+
+    var longtext = text1.length > text2.length ? text1 : text2;
+    var shorttext = text1.length > text2.length ? text2 : text1;
+    var i = longtext.indexOf(shorttext);
+    if (i != -1) {
+      // Shorter text is inside the longer text (speedup).
+      diffs = [[DIFF_INSERT, longtext.substring(0, i)],
+               [DIFF_EQUAL, shorttext],
+               [DIFF_INSERT, longtext.substring(i + shorttext.length)]];
+      // Swap insertions for deletions if diff is reversed.
+      if (text1.length > text2.length) {
+        diffs[0][0] = diffs[2][0] = DIFF_DELETE;
+      }
+      return diffs;
+    }
+
+    if (shorttext.length == 1) {
+      // Single character string.
+      // After the previous speedup, the character can't be an equality.
+      return [[DIFF_DELETE, text1], [DIFF_INSERT, text2]];
+    }
+    longtext = shorttext = null;  // Garbage collect.
+
+    // Check to see if the problem can be split in two.
+    var hm = this.diff_halfMatch_(text1, text2);
+    if (hm) {
+      // A half-match was found, sort out the return data.
+      var text1_a = hm[0];
+      var text1_b = hm[1];
+      var text2_a = hm[2];
+      var text2_b = hm[3];
+      var mid_common = hm[4];
+      // Send both pairs off for separate processing.
+      var diffs_a = this.diff_main(text1_a, text2_a, checklines, deadline);
+      var diffs_b = this.diff_main(text1_b, text2_b, checklines, deadline);
+      // Merge the results.
+      return diffs_a.concat([[DIFF_EQUAL, mid_common]], diffs_b);
+    }
+
+    if (checklines && text1.length > 100 && text2.length > 100) {
+      return this.diff_lineMode_(text1, text2, deadline);
+    }
+
+    return this.diff_bisect_(text1, text2, deadline);
+  };
+
+
+  /**
+   * Do a quick line-level diff on both strings, then rediff the parts for
+   * greater accuracy.
+   * This speedup can produce non-minimal diffs.
+   * @param {string} text1 Old string to be diffed.
+   * @param {string} text2 New string to be diffed.
+   * @param {number} deadline Time when the diff should be complete by.
+   * @return {!Array.<!diff_match_patch.Diff>} Array of diff tuples.
+   * @private
+   */
+  diff_match_patch.prototype.diff_lineMode_ = function(text1, text2, deadline) {
+    // Scan the text on a line-by-line basis first.
+    var a = this.diff_linesToChars_(text1, text2);
+    text1 = /** @type {string} */(a[0]);
+    text2 = /** @type {string} */(a[1]);
+    var linearray = /** @type {!Array.<string>} */(a[2]);
+
+    var diffs = this.diff_bisect_(text1, text2, deadline);
+
+    // Convert the diff back to original text.
+    this.diff_charsToLines_(diffs, linearray);
+    // Eliminate freak matches (e.g. blank lines)
+    this.diff_cleanupSemantic(diffs);
+
+    // Rediff any replacement blocks, this time character-by-character.
+    // Add a dummy entry at the end.
+    diffs.push([DIFF_EQUAL, '']);
+    var pointer = 0;
+    var count_delete = 0;
+    var count_insert = 0;
+    var text_delete = '';
+    var text_insert = '';
+    while (pointer < diffs.length) {
+      switch (diffs[pointer][0]) {
+        case DIFF_INSERT:
+          count_insert++;
+          text_insert += diffs[pointer][1];
+          break;
+        case DIFF_DELETE:
+          count_delete++;
+          text_delete += diffs[pointer][1];
+          break;
+        case DIFF_EQUAL:
+          // Upon reaching an equality, check for prior redundancies.
+          if (count_delete >= 1 && count_insert >= 1) {
+            // Delete the offending records and add the merged ones.
+            var a = this.diff_main(text_delete, text_insert, false, deadline);
+            diffs.splice(pointer - count_delete - count_insert,
+                         count_delete + count_insert);
+            pointer = pointer - count_delete - count_insert;
+            for (var j = a.length - 1; j >= 0; j--) {
+              diffs.splice(pointer, 0, a[j]);
+            }
+            pointer = pointer + a.length;
+          }
+          count_insert = 0;
+          count_delete = 0;
+          text_delete = '';
+          text_insert = '';
+          break;
+      }
+      pointer++;
+    }
+    diffs.pop();  // Remove the dummy entry at the end.
+
+    return diffs;
+  };
+
+
+  /**
+   * Find the 'middle snake' of a diff, split the problem in two
+   * and return the recursively constructed diff.
+   * See Myers 1986 paper: An O(ND) Difference Algorithm and Its Variations.
+   * @param {string} text1 Old string to be diffed.
+   * @param {string} text2 New string to be diffed.
+   * @param {number} deadline Time at which to bail if not yet complete.
+   * @return {!Array.<!diff_match_patch.Diff>} Array of diff tuples.
+   * @private
+   */
+  diff_match_patch.prototype.diff_bisect_ = function(text1, text2, deadline) {
+    // Cache the text lengths to prevent multiple calls.
+    var text1_length = text1.length;
+    var text2_length = text2.length;
+    var max_d = Math.ceil((text1_length + text2_length) / 2);
+    var v_offset = max_d;
+    var v_length = 2 * max_d;
+    var v1 = new Array(v_length);
+    var v2 = new Array(v_length);
+    // Setting all elements to -1 is faster in Chrome & Firefox than mixing
+    // integers and undefined.
+    for (var x = 0; x < v_length; x++) {
+      v1[x] = -1;
+      v2[x] = -1;
+    }
+    v1[v_offset + 1] = 0;
+    v2[v_offset + 1] = 0;
+    var delta = text1_length - text2_length;
+    // If the total number of characters is odd, then the front path will collide
+    // with the reverse path.
+    var front = (delta % 2 != 0);
+    // Offsets for start and end of k loop.
+    // Prevents mapping of space beyond the grid.
+    var k1start = 0;
+    var k1end = 0;
+    var k2start = 0;
+    var k2end = 0;
+    for (var d = 0; d < max_d; d++) {
+      // Bail out if deadline is reached.
+      if ((new Date()).getTime() > deadline) {
+        break;
+      }
+
+      // Walk the front path one step.
+      for (var k1 = -d + k1start; k1 <= d - k1end; k1 += 2) {
+        var k1_offset = v_offset + k1;
+        var x1;
+        if (k1 == -d || k1 != d && v1[k1_offset - 1] < v1[k1_offset + 1]) {
+          x1 = v1[k1_offset + 1];
+        } else {
+          x1 = v1[k1_offset - 1] + 1;
+        }
+        var y1 = x1 - k1;
+        while (x1 < text1_length && y1 < text2_length &&
+               text1.charAt(x1) == text2.charAt(y1)) {
+          x1++;
+          y1++;
+        }
+        v1[k1_offset] = x1;
+        if (x1 > text1_length) {
+          // Ran off the right of the graph.
+          k1end += 2;
+        } else if (y1 > text2_length) {
+          // Ran off the bottom of the graph.
+          k1start += 2;
+        } else if (front) {
+          var k2_offset = v_offset + delta - k1;
+          if (k2_offset >= 0 && k2_offset < v_length && v2[k2_offset] != -1) {
+            // Mirror x2 onto top-left coordinate system.
+            var x2 = text1_length - v2[k2_offset];
+            if (x1 >= x2) {
+              // Overlap detected.
+              return this.diff_bisectSplit_(text1, text2, x1, y1, deadline);
+            }
+          }
+        }
+      }
+
+      // Walk the reverse path one step.
+      for (var k2 = -d + k2start; k2 <= d - k2end; k2 += 2) {
+        var k2_offset = v_offset + k2;
+        var x2;
+        if (k2 == -d || k2 != d && v2[k2_offset - 1] < v2[k2_offset + 1]) {
+          x2 = v2[k2_offset + 1];
+        } else {
+          x2 = v2[k2_offset - 1] + 1;
+        }
+        var y2 = x2 - k2;
+        while (x2 < text1_length && y2 < text2_length &&
+               text1.charAt(text1_length - x2 - 1) ==
+               text2.charAt(text2_length - y2 - 1)) {
+          x2++;
+          y2++;
+        }
+        v2[k2_offset] = x2;
+        if (x2 > text1_length) {
+          // Ran off the left of the graph.
+          k2end += 2;
+        } else if (y2 > text2_length) {
+          // Ran off the top of the graph.
+          k2start += 2;
+        } else if (!front) {
+          var k1_offset = v_offset + delta - k2;
+          if (k1_offset >= 0 && k1_offset < v_length && v1[k1_offset] != -1) {
+            var x1 = v1[k1_offset];
+            var y1 = v_offset + x1 - k1_offset;
+            // Mirror x2 onto top-left coordinate system.
+            x2 = text1_length - x2;
+            if (x1 >= x2) {
+              // Overlap detected.
+              return this.diff_bisectSplit_(text1, text2, x1, y1, deadline);
+            }
+          }
+        }
+      }
+    }
+    // Diff took too long and hit the deadline or
+    // number of diffs equals number of characters, no commonality at all.
+    return [[DIFF_DELETE, text1], [DIFF_INSERT, text2]];
+  };
+
+
+  /**
+   * Given the location of the 'middle snake', split the diff in two parts
+   * and recurse.
+   * @param {string} text1 Old string to be diffed.
+   * @param {string} text2 New string to be diffed.
+   * @param {number} x Index of split point in text1.
+   * @param {number} y Index of split point in text2.
+   * @param {number} deadline Time at which to bail if not yet complete.
+   * @return {!Array.<!diff_match_patch.Diff>} Array of diff tuples.
+   * @private
+   */
+  diff_match_patch.prototype.diff_bisectSplit_ = function(text1, text2, x, y,
+      deadline) {
+    var text1a = text1.substring(0, x);
+    var text2a = text2.substring(0, y);
+    var text1b = text1.substring(x);
+    var text2b = text2.substring(y);
+
+    // Compute both diffs serially.
+    var diffs = this.diff_main(text1a, text2a, false, deadline);
+    var diffsb = this.diff_main(text1b, text2b, false, deadline);
+
+    return diffs.concat(diffsb);
+  };
+
+
+  /**
+   * Split two texts into an array of strings.  Reduce the texts to a string of
+   * hashes where each Unicode character represents one line.
+   * @param {string} text1 First string.
+   * @param {string} text2 Second string.
+   * @return {!Array.<string|!Array.<string>>} Three element Array, containing the
+   *     encoded text1, the encoded text2 and the array of unique strings.  The
+   *     zeroth element of the array of unique strings is intentionally blank.
+   * @private
+   */
+  diff_match_patch.prototype.diff_linesToChars_ = function(text1, text2) {
+    var lineArray = [];  // e.g. lineArray[4] == 'Hello\n'
+    var lineHash = {};   // e.g. lineHash['Hello\n'] == 4
+
+    // '\x00' is a valid character, but various debuggers don't like it.
+    // So we'll insert a junk entry to avoid generating a null character.
+    lineArray[0] = '';
+
+    /**
+     * Split a text into an array of strings.  Reduce the texts to a string of
+     * hashes where each Unicode character represents one line.
+     * Modifies linearray and linehash through being a closure.
+     * @param {string} text String to encode.
+     * @return {string} Encoded string.
+     * @private
+     */
+    function diff_linesToCharsMunge_(text) {
+      var chars = '';
+      // Walk the text, pulling out a substring for each line.
+      // text.split('\n') would would temporarily double our memory footprint.
+      // Modifying text would create many large strings to garbage collect.
+      var lineStart = 0;
+      var lineEnd = -1;
+      // Keeping our own length variable is faster than looking it up.
+      var lineArrayLength = lineArray.length;
+      while (lineEnd < text.length - 1) {
+        lineEnd = text.indexOf('\n', lineStart);
+        if (lineEnd == -1) {
+          lineEnd = text.length - 1;
+        }
+        var line = text.substring(lineStart, lineEnd + 1);
+        lineStart = lineEnd + 1;
+
+        if (lineHash.hasOwnProperty ? lineHash.hasOwnProperty(line) :
+            (lineHash[line] !== undefined)) {
+          chars += String.fromCharCode(lineHash[line]);
+        } else {
+          chars += String.fromCharCode(lineArrayLength);
+          lineHash[line] = lineArrayLength;
+          lineArray[lineArrayLength++] = line;
+        }
+      }
+      return chars;
+    }
+
+    var chars1 = diff_linesToCharsMunge_(text1);
+    var chars2 = diff_linesToCharsMunge_(text2);
+    return [chars1, chars2, lineArray];
+  };
+
+
+  /**
+   * Rehydrate the text in a diff from a string of line hashes to real lines of
+   * text.
+   * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+   * @param {!Array.<string>} lineArray Array of unique strings.
+   * @private
+   */
+  diff_match_patch.prototype.diff_charsToLines_ = function(diffs, lineArray) {
+    for (var x = 0; x < diffs.length; x++) {
+      var chars = diffs[x][1];
+      var text = [];
+      for (var y = 0; y < chars.length; y++) {
+        text[y] = lineArray[chars.charCodeAt(y)];
+      }
+      diffs[x][1] = text.join('');
+    }
+  };
+
+
+  /**
+   * Determine the common prefix of two strings.
+   * @param {string} text1 First string.
+   * @param {string} text2 Second string.
+   * @return {number} The number of characters common to the start of each
+   *     string.
+   */
+  diff_match_patch.prototype.diff_commonPrefix = function(text1, text2) {
+    // Quick check for common null cases.
+    if (!text1 || !text2 || text1.charAt(0) != text2.charAt(0)) {
+      return 0;
+    }
+    // Binary search.
+    // Performance analysis: http://neil.fraser.name/news/2007/10/09/
+    var pointermin = 0;
+    var pointermax = Math.min(text1.length, text2.length);
+    var pointermid = pointermax;
+    var pointerstart = 0;
+    while (pointermin < pointermid) {
+      if (text1.substring(pointerstart, pointermid) ==
+          text2.substring(pointerstart, pointermid)) {
+        pointermin = pointermid;
+        pointerstart = pointermin;
+      } else {
+        pointermax = pointermid;
+      }
+      pointermid = Math.floor((pointermax - pointermin) / 2 + pointermin);
+    }
+    return pointermid;
+  };
+
+
+  /**
+   * Determine the common suffix of two strings.
+   * @param {string} text1 First string.
+   * @param {string} text2 Second string.
+   * @return {number} The number of characters common to the end of each string.
+   */
+  diff_match_patch.prototype.diff_commonSuffix = function(text1, text2) {
+    // Quick check for common null cases.
+    if (!text1 || !text2 ||
+        text1.charAt(text1.length - 1) != text2.charAt(text2.length - 1)) {
+      return 0;
+    }
+    // Binary search.
+    // Performance analysis: http://neil.fraser.name/news/2007/10/09/
+    var pointermin = 0;
+    var pointermax = Math.min(text1.length, text2.length);
+    var pointermid = pointermax;
+    var pointerend = 0;
+    while (pointermin < pointermid) {
+      if (text1.substring(text1.length - pointermid, text1.length - pointerend) ==
+          text2.substring(text2.length - pointermid, text2.length - pointerend)) {
+        pointermin = pointermid;
+        pointerend = pointermin;
+      } else {
+        pointermax = pointermid;
+      }
+      pointermid = Math.floor((pointermax - pointermin) / 2 + pointermin);
+    }
+    return pointermid;
+  };
+
+
+  /**
+   * Determine if the suffix of one string is the prefix of another.
+   * @param {string} text1 First string.
+   * @param {string} text2 Second string.
+   * @return {number} The number of characters common to the end of the first
+   *     string and the start of the second string.
+   * @private
+   */
+  diff_match_patch.prototype.diff_commonOverlap_ = function(text1, text2) {
+    // Cache the text lengths to prevent multiple calls.
+    var text1_length = text1.length;
+    var text2_length = text2.length;
+    // Eliminate the null case.
+    if (text1_length == 0 || text2_length == 0) {
+      return 0;
+    }
+    // Truncate the longer string.
+    if (text1_length > text2_length) {
+      text1 = text1.substring(text1_length - text2_length);
+    } else if (text1_length < text2_length) {
+      text2 = text2.substring(0, text1_length);
+    }
+    var text_length = Math.min(text1_length, text2_length);
+    // Quick check for the worst case.
+    if (text1 == text2) {
+      return text_length;
+    }
+
+    // Start by looking for a single character match
+    // and increase length until no match is found.
+    // Performance analysis: http://neil.fraser.name/news/2010/11/04/
+    var best = 0;
+    var length = 1;
+    while (true) {
+      var pattern = text1.substring(text_length - length);
+      var found = text2.indexOf(pattern);
+      if (found == -1) {
+        return best;
+      }
+      length += found;
+      if (found == 0 || text1.substring(text_length - length) ==
+          text2.substring(0, length)) {
+        best = length;
+        length++;
+      }
+    }
+  };
+
+
+  /**
+   * Do the two texts share a substring which is at least half the length of the
+   * longer text?
+   * This speedup can produce non-minimal diffs.
+   * @param {string} text1 First string.
+   * @param {string} text2 Second string.
+   * @return {Array.<string>} Five element Array, containing the prefix of
+   *     text1, the suffix of text1, the prefix of text2, the suffix of
+   *     text2 and the common middle.  Or null if there was no match.
+   * @private
+   */
+  diff_match_patch.prototype.diff_halfMatch_ = function(text1, text2) {
+    if (this.Diff_Timeout <= 0) {
+      // Don't risk returning a non-optimal diff if we have unlimited time.
+      return null;
+    }
+    var longtext = text1.length > text2.length ? text1 : text2;
+    var shorttext = text1.length > text2.length ? text2 : text1;
+    if (longtext.length < 4 || shorttext.length * 2 < longtext.length) {
+      return null;  // Pointless.
+    }
+    var dmp = this;  // 'this' becomes 'window' in a closure.
+
+    /**
+     * Does a substring of shorttext exist within longtext such that the substring
+     * is at least half the length of longtext?
+     * Closure, but does not reference any external variables.
+     * @param {string} longtext Longer string.
+     * @param {string} shorttext Shorter string.
+     * @param {number} i Start index of quarter length substring within longtext.
+     * @return {Array.<string>} Five element Array, containing the prefix of
+     *     longtext, the suffix of longtext, the prefix of shorttext, the suffix
+     *     of shorttext and the common middle.  Or null if there was no match.
+     * @private
+     */
+    function diff_halfMatchI_(longtext, shorttext, i) {
+      // Start with a 1/4 length substring at position i as a seed.
+      var seed = longtext.substring(i, i + Math.floor(longtext.length / 4));
+      var j = -1;
+      var best_common = '';
+      var best_longtext_a, best_longtext_b, best_shorttext_a, best_shorttext_b;
+      while ((j = shorttext.indexOf(seed, j + 1)) != -1) {
+        var prefixLength = dmp.diff_commonPrefix(longtext.substring(i),
+                                                 shorttext.substring(j));
+        var suffixLength = dmp.diff_commonSuffix(longtext.substring(0, i),
+                                                 shorttext.substring(0, j));
+        if (best_common.length < suffixLength + prefixLength) {
+          best_common = shorttext.substring(j - suffixLength, j) +
+              shorttext.substring(j, j + prefixLength);
+          best_longtext_a = longtext.substring(0, i - suffixLength);
+          best_longtext_b = longtext.substring(i + prefixLength);
+          best_shorttext_a = shorttext.substring(0, j - suffixLength);
+          best_shorttext_b = shorttext.substring(j + prefixLength);
+        }
+      }
+      if (best_common.length * 2 >= longtext.length) {
+        return [best_longtext_a, best_longtext_b,
+                best_shorttext_a, best_shorttext_b, best_common];
+      } else {
+        return null;
+      }
+    }
+
+    // First check if the second quarter is the seed for a half-match.
+    var hm1 = diff_halfMatchI_(longtext, shorttext,
+                               Math.ceil(longtext.length / 4));
+    // Check again based on the third quarter.
+    var hm2 = diff_halfMatchI_(longtext, shorttext,
+                               Math.ceil(longtext.length / 2));
+    var hm;
+    if (!hm1 && !hm2) {
+      return null;
+    } else if (!hm2) {
+      hm = hm1;
+    } else if (!hm1) {
+      hm = hm2;
+    } else {
+      // Both matched.  Select the longest.
+      hm = hm1[4].length > hm2[4].length ? hm1 : hm2;
+    }
+
+    // A half-match was found, sort out the return data.
+    var text1_a, text1_b, text2_a, text2_b;
+    if (text1.length > text2.length) {
+      text1_a = hm[0];
+      text1_b = hm[1];
+      text2_a = hm[2];
+      text2_b = hm[3];
+    } else {
+      text2_a = hm[0];
+      text2_b = hm[1];
+      text1_a = hm[2];
+      text1_b = hm[3];
+    }
+    var mid_common = hm[4];
+    return [text1_a, text1_b, text2_a, text2_b, mid_common];
+  };
+
+
+  /**
+   * Reduce the number of edits by eliminating semantically trivial equalities.
+   * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+   */
+  diff_match_patch.prototype.diff_cleanupSemantic = function(diffs) {
+    var changes = false;
+    var equalities = [];  // Stack of indices where equalities are found.
+    var equalitiesLength = 0;  // Keeping our own length var is faster in JS.
+    /** @type {?string} */
+    var lastequality = null;  // Always equal to equalities[equalitiesLength-1][1]
+    var pointer = 0;  // Index of current position.
+    // Number of characters that changed prior to the equality.
+    var length_insertions1 = 0;
+    var length_deletions1 = 0;
+    // Number of characters that changed after the equality.
+    var length_insertions2 = 0;
+    var length_deletions2 = 0;
+    while (pointer < diffs.length) {
+      if (diffs[pointer][0] == DIFF_EQUAL) {  // Equality found.
+        equalities[equalitiesLength++] = pointer;
+        length_insertions1 = length_insertions2;
+        length_deletions1 = length_deletions2;
+        length_insertions2 = 0;
+        length_deletions2 = 0;
+        lastequality = /** @type {string} */(diffs[pointer][1]);
+      } else {  // An insertion or deletion.
+        if (diffs[pointer][0] == DIFF_INSERT) {
+          length_insertions2 += diffs[pointer][1].length;
+        } else {
+          length_deletions2 += diffs[pointer][1].length;
+        }
+        // Eliminate an equality that is smaller or equal to the edits on both
+        // sides of it.
+        if (lastequality !== null && (lastequality.length <=
+            Math.max(length_insertions1, length_deletions1)) &&
+            (lastequality.length <= Math.max(length_insertions2,
+                                             length_deletions2))) {
+          // Duplicate record.
+          diffs.splice(equalities[equalitiesLength - 1], 0,
+                       [DIFF_DELETE, lastequality]);
+          // Change second copy to insert.
+          diffs[equalities[equalitiesLength - 1] + 1][0] = DIFF_INSERT;
+          // Throw away the equality we just deleted.
+          equalitiesLength--;
+          // Throw away the previous equality (it needs to be reevaluated).
+          equalitiesLength--;
+          pointer = equalitiesLength > 0 ? equalities[equalitiesLength - 1] : -1;
+          length_insertions1 = 0;  // Reset the counters.
+          length_deletions1 = 0;
+          length_insertions2 = 0;
+          length_deletions2 = 0;
+          lastequality = null;
+          changes = true;
+        }
+      }
+      pointer++;
+    }
+
+    // Normalize the diff.
+    if (changes) {
+      this.diff_cleanupMerge(diffs);
+    }
+    this.diff_cleanupSemanticLossless(diffs);
+
+    // Find any overlaps between deletions and insertions.
+    // e.g: <del>abcxxx</del><ins>xxxdef</ins>
+    //   -> <del>abc</del>xxx<ins>def</ins>
+    // Only extract an overlap if it is as big as the edit ahead or behind it.
+    pointer = 1;
+    while (pointer < diffs.length) {
+      if (diffs[pointer - 1][0] == DIFF_DELETE &&
+          diffs[pointer][0] == DIFF_INSERT) {
+        var deletion = /** @type {string} */(diffs[pointer - 1][1]);
+        var insertion = /** @type {string} */(diffs[pointer][1]);
+        var overlap_length = this.diff_commonOverlap_(deletion, insertion);
+        if (overlap_length >= deletion.length / 2 ||
+            overlap_length >= insertion.length / 2) {
+          // Overlap found.  Insert an equality and trim the surrounding edits.
+          diffs.splice(pointer, 0,
+              [DIFF_EQUAL, insertion.substring(0, overlap_length)]);
+          diffs[pointer - 1][1] =
+              deletion.substring(0, deletion.length - overlap_length);
+          diffs[pointer + 1][1] = insertion.substring(overlap_length);
+          pointer++;
+        }
+        pointer++;
+      }
+      pointer++;
+    }
+  };
+
+
+  /**
+   * Look for single edits surrounded on both sides by equalities
+   * which can be shifted sideways to align the edit to a word boundary.
+   * e.g: The c<ins>at c</ins>ame. -> The <ins>cat </ins>came.
+   * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+   */
+  diff_match_patch.prototype.diff_cleanupSemanticLossless = function(diffs) {
+    // Define some regex patterns for matching boundaries.
+    var punctuation = /[^a-zA-Z0-9]/;
+    var whitespace = /\s/;
+    var linebreak = /[\r\n]/;
+    var blanklineEnd = /\n\r?\n$/;
+    var blanklineStart = /^\r?\n\r?\n/;
+
+    /**
+     * Given two strings, compute a score representing whether the internal
+     * boundary falls on logical boundaries.
+     * Scores range from 5 (best) to 0 (worst).
+     * Closure, makes reference to regex patterns defined above.
+     * @param {string} one First string.
+     * @param {string} two Second string.
+     * @return {number} The score.
+     * @private
+     */
+    function diff_cleanupSemanticScore_(one, two) {
+      if (!one || !two) {
+        // Edges are the best.
+        return 5;
+      }
+
+      // Each port of this function behaves slightly differently due to
+      // subtle differences in each language's definition of things like
+      // 'whitespace'.  Since this function's purpose is largely cosmetic,
+      // the choice has been made to use each language's native features
+      // rather than force total conformity.
+      var score = 0;
+      // One point for non-alphanumeric.
+      if (one.charAt(one.length - 1).match(punctuation) ||
+          two.charAt(0).match(punctuation)) {
+        score++;
+        // Two points for whitespace.
+        if (one.charAt(one.length - 1).match(whitespace) ||
+            two.charAt(0).match(whitespace)) {
+          score++;
+          // Three points for line breaks.
+          if (one.charAt(one.length - 1).match(linebreak) ||
+              two.charAt(0).match(linebreak)) {
+            score++;
+            // Four points for blank lines.
+            if (one.match(blanklineEnd) || two.match(blanklineStart)) {
+              score++;
+            }
+          }
+        }
+      }
+      return score;
+    }
+
+    var pointer = 1;
+    // Intentionally ignore the first and last element (don't need checking).
+    while (pointer < diffs.length - 1) {
+      if (diffs[pointer - 1][0] == DIFF_EQUAL &&
+          diffs[pointer + 1][0] == DIFF_EQUAL) {
+        // This is a single edit surrounded by equalities.
+        var equality1 = /** @type {string} */(diffs[pointer - 1][1]);
+        var edit = /** @type {string} */(diffs[pointer][1]);
+        var equality2 = /** @type {string} */(diffs[pointer + 1][1]);
+
+        // First, shift the edit as far left as possible.
+        var commonOffset = this.diff_commonSuffix(equality1, edit);
+        if (commonOffset) {
+          var commonString = edit.substring(edit.length - commonOffset);
+          equality1 = equality1.substring(0, equality1.length - commonOffset);
+          edit = commonString + edit.substring(0, edit.length - commonOffset);
+          equality2 = commonString + equality2;
+        }
+
+        // Second, step character by character right, looking for the best fit.
+        var bestEquality1 = equality1;
+        var bestEdit = edit;
+        var bestEquality2 = equality2;
+        var bestScore = diff_cleanupSemanticScore_(equality1, edit) +
+            diff_cleanupSemanticScore_(edit, equality2);
+        while (edit.charAt(0) === equality2.charAt(0)) {
+          equality1 += edit.charAt(0);
+          edit = edit.substring(1) + equality2.charAt(0);
+          equality2 = equality2.substring(1);
+          var score = diff_cleanupSemanticScore_(equality1, edit) +
+              diff_cleanupSemanticScore_(edit, equality2);
+          // The >= encourages trailing rather than leading whitespace on edits.
+          if (score >= bestScore) {
+            bestScore = score;
+            bestEquality1 = equality1;
+            bestEdit = edit;
+            bestEquality2 = equality2;
+          }
+        }
+
+        if (diffs[pointer - 1][1] != bestEquality1) {
+          // We have an improvement, save it back to the diff.
+          if (bestEquality1) {
+            diffs[pointer - 1][1] = bestEquality1;
+          } else {
+            diffs.splice(pointer - 1, 1);
+            pointer--;
+          }
+          diffs[pointer][1] = bestEdit;
+          if (bestEquality2) {
+            diffs[pointer + 1][1] = bestEquality2;
+          } else {
+            diffs.splice(pointer + 1, 1);
+            pointer--;
+          }
+        }
+      }
+      pointer++;
+    }
+  };
+
+
+  /**
+   * Reduce the number of edits by eliminating operationally trivial equalities.
+   * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+   */
+  diff_match_patch.prototype.diff_cleanupEfficiency = function(diffs) {
+    var changes = false;
+    var equalities = [];  // Stack of indices where equalities are found.
+    var equalitiesLength = 0;  // Keeping our own length var is faster in JS.
+    var lastequality = '';  // Always equal to equalities[equalitiesLength-1][1]
+    var pointer = 0;  // Index of current position.
+    // Is there an insertion operation before the last equality.
+    var pre_ins = false;
+    // Is there a deletion operation before the last equality.
+    var pre_del = false;
+    // Is there an insertion operation after the last equality.
+    var post_ins = false;
+    // Is there a deletion operation after the last equality.
+    var post_del = false;
+    while (pointer < diffs.length) {
+      if (diffs[pointer][0] == DIFF_EQUAL) {  // Equality found.
+        if (diffs[pointer][1].length < this.Diff_EditCost &&
+            (post_ins || post_del)) {
+          // Candidate found.
+          equalities[equalitiesLength++] = pointer;
+          pre_ins = post_ins;
+          pre_del = post_del;
+          lastequality = diffs[pointer][1];
+        } else {
+          // Not a candidate, and can never become one.
+          equalitiesLength = 0;
+          lastequality = '';
+        }
+        post_ins = post_del = false;
+      } else {  // An insertion or deletion.
+        if (diffs[pointer][0] == DIFF_DELETE) {
+          post_del = true;
+        } else {
+          post_ins = true;
+        }
+        /*
+         * Five types to be split:
+         * <ins>A</ins><del>B</del>XY<ins>C</ins><del>D</del>
+         * <ins>A</ins>X<ins>C</ins><del>D</del>
+         * <ins>A</ins><del>B</del>X<ins>C</ins>
+         * <ins>A</del>X<ins>C</ins><del>D</del>
+         * <ins>A</ins><del>B</del>X<del>C</del>
+         */
+        if (lastequality && ((pre_ins && pre_del && post_ins && post_del) ||
+                             ((lastequality.length < this.Diff_EditCost / 2) &&
+                              (pre_ins + pre_del + post_ins + post_del) == 3))) {
+          // Duplicate record.
+          diffs.splice(equalities[equalitiesLength - 1], 0,
+                       [DIFF_DELETE, lastequality]);
+          // Change second copy to insert.
+          diffs[equalities[equalitiesLength - 1] + 1][0] = DIFF_INSERT;
+          equalitiesLength--;  // Throw away the equality we just deleted;
+          lastequality = '';
+          if (pre_ins && pre_del) {
+            // No changes made which could affect previous entry, keep going.
+            post_ins = post_del = true;
+            equalitiesLength = 0;
+          } else {
+            equalitiesLength--;  // Throw away the previous equality.
+            pointer = equalitiesLength > 0 ?
+                equalities[equalitiesLength - 1] : -1;
+            post_ins = post_del = false;
+          }
+          changes = true;
+        }
+      }
+      pointer++;
+    }
+
+    if (changes) {
+      this.diff_cleanupMerge(diffs);
+    }
+  };
+
+
+  /**
+   * Reorder and merge like edit sections.  Merge equalities.
+   * Any edit section can move as long as it doesn't cross an equality.
+   * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+   */
+  diff_match_patch.prototype.diff_cleanupMerge = function(diffs) {
+    diffs.push([DIFF_EQUAL, '']);  // Add a dummy entry at the end.
+    var pointer = 0;
+    var count_delete = 0;
+    var count_insert = 0;
+    var text_delete = '';
+    var text_insert = '';
+    var commonlength;
+    while (pointer < diffs.length) {
+      switch (diffs[pointer][0]) {
+        case DIFF_INSERT:
+          count_insert++;
+          text_insert += diffs[pointer][1];
+          pointer++;
+          break;
+        case DIFF_DELETE:
+          count_delete++;
+          text_delete += diffs[pointer][1];
+          pointer++;
+          break;
+        case DIFF_EQUAL:
+          // Upon reaching an equality, check for prior redundancies.
+          if (count_delete + count_insert > 1) {
+            if (count_delete !== 0 && count_insert !== 0) {
+              // Factor out any common prefixies.
+              commonlength = this.diff_commonPrefix(text_insert, text_delete);
+              if (commonlength !== 0) {
+                if ((pointer - count_delete - count_insert) > 0 &&
+                    diffs[pointer - count_delete - count_insert - 1][0] ==
+                    DIFF_EQUAL) {
+                  diffs[pointer - count_delete - count_insert - 1][1] +=
+                      text_insert.substring(0, commonlength);
+                } else {
+                  diffs.splice(0, 0, [DIFF_EQUAL,
+                                      text_insert.substring(0, commonlength)]);
+                  pointer++;
+                }
+                text_insert = text_insert.substring(commonlength);
+                text_delete = text_delete.substring(commonlength);
+              }
+              // Factor out any common suffixies.
+              commonlength = this.diff_commonSuffix(text_insert, text_delete);
+              if (commonlength !== 0) {
+                diffs[pointer][1] = text_insert.substring(text_insert.length -
+                    commonlength) + diffs[pointer][1];
+                text_insert = text_insert.substring(0, text_insert.length -
+                    commonlength);
+                text_delete = text_delete.substring(0, text_delete.length -
+                    commonlength);
+              }
+            }
+            // Delete the offending records and add the merged ones.
+            if (count_delete === 0) {
+              diffs.splice(pointer - count_delete - count_insert,
+                  count_delete + count_insert, [DIFF_INSERT, text_insert]);
+            } else if (count_insert === 0) {
+              diffs.splice(pointer - count_delete - count_insert,
+                  count_delete + count_insert, [DIFF_DELETE, text_delete]);
+            } else {
+              diffs.splice(pointer - count_delete - count_insert,
+                  count_delete + count_insert, [DIFF_DELETE, text_delete],
+                  [DIFF_INSERT, text_insert]);
+            }
+            pointer = pointer - count_delete - count_insert +
+                      (count_delete ? 1 : 0) + (count_insert ? 1 : 0) + 1;
+          } else if (pointer !== 0 && diffs[pointer - 1][0] == DIFF_EQUAL) {
+            // Merge this equality with the previous one.
+            diffs[pointer - 1][1] += diffs[pointer][1];
+            diffs.splice(pointer, 1);
+          } else {
+            pointer++;
+          }
+          count_insert = 0;
+          count_delete = 0;
+          text_delete = '';
+          text_insert = '';
+          break;
+      }
+    }
+    if (diffs[diffs.length - 1][1] === '') {
+      diffs.pop();  // Remove the dummy entry at the end.
+    }
+
+    // Second pass: look for single edits surrounded on both sides by equalities
+    // which can be shifted sideways to eliminate an equality.
+    // e.g: A<ins>BA</ins>C -> <ins>AB</ins>AC
+    var changes = false;
+    pointer = 1;
+    // Intentionally ignore the first and last element (don't need checking).
+    while (pointer < diffs.length - 1) {
+      if (diffs[pointer - 1][0] == DIFF_EQUAL &&
+          diffs[pointer + 1][0] == DIFF_EQUAL) {
+        // This is a single edit surrounded by equalities.
+        if (diffs[pointer][1].substring(diffs[pointer][1].length -
+            diffs[pointer - 1][1].length) == diffs[pointer - 1][1]) {
+          // Shift the edit over the previous equality.
+          diffs[pointer][1] = diffs[pointer - 1][1] +
+              diffs[pointer][1].substring(0, diffs[pointer][1].length -
+                                          diffs[pointer - 1][1].length);
+          diffs[pointer + 1][1] = diffs[pointer - 1][1] + diffs[pointer + 1][1];
+          diffs.splice(pointer - 1, 1);
+          changes = true;
+        } else if (diffs[pointer][1].substring(0, diffs[pointer + 1][1].length) ==
+            diffs[pointer + 1][1]) {
+          // Shift the edit over the next equality.
+          diffs[pointer - 1][1] += diffs[pointer + 1][1];
+          diffs[pointer][1] =
+              diffs[pointer][1].substring(diffs[pointer + 1][1].length) +
+              diffs[pointer + 1][1];
+          diffs.splice(pointer + 1, 1);
+          changes = true;
+        }
+      }
+      pointer++;
+    }
+    // If shifts were made, the diff needs reordering and another shift sweep.
+    if (changes) {
+      this.diff_cleanupMerge(diffs);
+    }
+  };
+
+
+  /**
+   * loc is a location in text1, compute and return the equivalent location in
+   * text2.
+   * e.g. 'The cat' vs 'The big cat', 1->1, 5->8
+   * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+   * @param {number} loc Location within text1.
+   * @return {number} Location within text2.
+   */
+  diff_match_patch.prototype.diff_xIndex = function(diffs, loc) {
+    var chars1 = 0;
+    var chars2 = 0;
+    var last_chars1 = 0;
+    var last_chars2 = 0;
+    var x;
+    for (x = 0; x < diffs.length; x++) {
+      if (diffs[x][0] !== DIFF_INSERT) {  // Equality or deletion.
+        chars1 += diffs[x][1].length;
+      }
+      if (diffs[x][0] !== DIFF_DELETE) {  // Equality or insertion.
+        chars2 += diffs[x][1].length;
+      }
+      if (chars1 > loc) {  // Overshot the location.
+        break;
+      }
+      last_chars1 = chars1;
+      last_chars2 = chars2;
+    }
+    // Was the location was deleted?
+    if (diffs.length != x && diffs[x][0] === DIFF_DELETE) {
+      return last_chars2;
+    }
+    // Add the remaining character length.
+    return last_chars2 + (loc - last_chars1);
+  };
+
+
+  /**
+   * Convert a diff array into a pretty HTML report.
+   * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+   * @return {string} HTML representation.
+   */
+  diff_match_patch.prototype.diff_prettyHtml = function(diffs) {
+    var html = [];
+    var i = 0;
+    var pattern_amp = /&/g;
+    var pattern_lt = /</g;
+    var pattern_gt = />/g;
+    var pattern_para = /\n/g;
+    for (var x = 0; x < diffs.length; x++) {
+      var op = diffs[x][0];    // Operation (insert, delete, equal)
+      var data = diffs[x][1];  // Text of change.
+      var text = data.replace(pattern_amp, '&amp;').replace(pattern_lt, '&lt;')
+          .replace(pattern_gt, '&gt;').replace(pattern_para, '&para;<br>');
+      switch (op) {
+        case DIFF_INSERT:
+          html[x] = '<ins style="background:#e6ffe6;">' + text + '</ins>';
+          break;
+        case DIFF_DELETE:
+          html[x] = '<del style="background:#ffe6e6;">' + text + '</del>';
+          break;
+        case DIFF_EQUAL:
+          html[x] = '<span>' + text + '</span>';
+          break;
+      }
+      if (op !== DIFF_DELETE) {
+        i += data.length;
+      }
+    }
+    return html.join('');
+  };
+
+
+  /**
+   * Compute and return the source text (all equalities and deletions).
+   * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+   * @return {string} Source text.
+   */
+  diff_match_patch.prototype.diff_text1 = function(diffs) {
+    var text = [];
+    for (var x = 0; x < diffs.length; x++) {
+      if (diffs[x][0] !== DIFF_INSERT) {
+        text[x] = diffs[x][1];
+      }
+    }
+    return text.join('');
+  };
+
+
+  /**
+   * Compute and return the destination text (all equalities and insertions).
+   * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+   * @return {string} Destination text.
+   */
+  diff_match_patch.prototype.diff_text2 = function(diffs) {
+    var text = [];
+    for (var x = 0; x < diffs.length; x++) {
+      if (diffs[x][0] !== DIFF_DELETE) {
+        text[x] = diffs[x][1];
+      }
+    }
+    return text.join('');
+  };
+
+
+  /**
+   * Compute the Levenshtein distance; the number of inserted, deleted or
+   * substituted characters.
+   * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+   * @return {number} Number of changes.
+   */
+  diff_match_patch.prototype.diff_levenshtein = function(diffs) {
+    var levenshtein = 0;
+    var insertions = 0;
+    var deletions = 0;
+    for (var x = 0; x < diffs.length; x++) {
+      var op = diffs[x][0];
+      var data = diffs[x][1];
+      switch (op) {
+        case DIFF_INSERT:
+          insertions += data.length;
+          break;
+        case DIFF_DELETE:
+          deletions += data.length;
+          break;
+        case DIFF_EQUAL:
+          // A deletion and an insertion is one substitution.
+          levenshtein += Math.max(insertions, deletions);
+          insertions = 0;
+          deletions = 0;
+          break;
+      }
+    }
+    levenshtein += Math.max(insertions, deletions);
+    return levenshtein;
+  };
+
+
+  /**
+   * Crush the diff into an encoded string which describes the operations
+   * required to transform text1 into text2.
+   * E.g. =3\t-2\t+ing  -> Keep 3 chars, delete 2 chars, insert 'ing'.
+   * Operations are tab-separated.  Inserted text is escaped using %xx notation.
+   * @param {!Array.<!diff_match_patch.Diff>} diffs Array of diff tuples.
+   * @return {string} Delta text.
+   */
+  diff_match_patch.prototype.diff_toDelta = function(diffs) {
+    var text = [];
+    for (var x = 0; x < diffs.length; x++) {
+      switch (diffs[x][0]) {
+        case DIFF_INSERT:
+          text[x] = '+' + encodeURI(diffs[x][1]);
+          break;
+        case DIFF_DELETE:
+          text[x] = '-' + diffs[x][1].length;
+          break;
+        case DIFF_EQUAL:
+          text[x] = '=' + diffs[x][1].length;
+          break;
+      }
+    }
+    return text.join('\t').replace(/%20/g, ' ');
+  };
+
+
+  /**
+   * Given the original text1, and an encoded string which describes the
+   * operations required to transform text1 into text2, compute the full diff.
+   * @param {string} text1 Source string for the diff.
+   * @param {string} delta Delta text.
+   * @return {!Array.<!diff_match_patch.Diff>} Array of diff tuples.
+   * @throws {!Error} If invalid input.
+   */
+  diff_match_patch.prototype.diff_fromDelta = function(text1, delta) {
+    var diffs = [];
+    var diffsLength = 0;  // Keeping our own length var is faster in JS.
+    var pointer = 0;  // Cursor in text1
+    var tokens = delta.split(/\t/g);
+    for (var x = 0; x < tokens.length; x++) {
+      // Each token begins with a one character parameter which specifies the
+      // operation of this token (delete, insert, equality).
+      var param = tokens[x].substring(1);
+      switch (tokens[x].charAt(0)) {
+        case '+':
+          try {
+            diffs[diffsLength++] = [DIFF_INSERT, decodeURI(param)];
+          } catch (ex) {
+            // Malformed URI sequence.
+            throw new Error('Illegal escape in diff_fromDelta: ' + param);
+          }
+          break;
+        case '-':
+          // Fall through.
+        case '=':
+          var n = parseInt(param, 10);
+          if (isNaN(n) || n < 0) {
+            throw new Error('Invalid number in diff_fromDelta: ' + param);
+          }
+          var text = text1.substring(pointer, pointer += n);
+          if (tokens[x].charAt(0) == '=') {
+            diffs[diffsLength++] = [DIFF_EQUAL, text];
+          } else {
+            diffs[diffsLength++] = [DIFF_DELETE, text];
+          }
+          break;
+        default:
+          // Blank tokens are ok (from a trailing \t).
+          // Anything else is an error.
+          if (tokens[x]) {
+            throw new Error('Invalid diff operation in diff_fromDelta: ' +
+                            tokens[x]);
+          }
+      }
+    }
+    if (pointer != text1.length) {
+      throw new Error('Delta length (' + pointer +
+          ') does not equal source text length (' + text1.length + ').');
+    }
+    return diffs;
+  };
+
+
+  //  MATCH FUNCTIONS
+
+
+  /**
+   * Locate the best instance of 'pattern' in 'text' near 'loc'.
+   * @param {string} text The text to search.
+   * @param {string} pattern The pattern to search for.
+   * @param {number} loc The location to search around.
+   * @return {number} Best match index or -1.
+   */
+  diff_match_patch.prototype.match_main = function(text, pattern, loc) {
+    // Check for null inputs.
+    if (text == null || pattern == null || loc == null) {
+      throw new Error('Null input. (match_main)');
+    }
+
+    loc = Math.max(0, Math.min(loc, text.length));
+    if (text == pattern) {
+      // Shortcut (potentially not guaranteed by the algorithm)
+      return 0;
+    } else if (!text.length) {
+      // Nothing to match.
+      return -1;
+    } else if (text.substring(loc, loc + pattern.length) == pattern) {
+      // Perfect match at the perfect spot!  (Includes case of null pattern)
+      return loc;
+    } else {
+      // Do a fuzzy compare.
+      return this.match_bitap_(text, pattern, loc);
+    }
+  };
+
+
+  /**
+   * Locate the best instance of 'pattern' in 'text' near 'loc' using the
+   * Bitap algorithm.
+   * @param {string} text The text to search.
+   * @param {string} pattern The pattern to search for.
+   * @param {number} loc The location to search around.
+   * @return {number} Best match index or -1.
+   * @private
+   */
+  diff_match_patch.prototype.match_bitap_ = function(text, pattern, loc) {
+    if (pattern.length > this.Match_MaxBits) {
+      throw new Error('Pattern too long for this browser.');
+    }
+
+    // Initialise the alphabet.
+    var s = this.match_alphabet_(pattern);
+
+    var dmp = this;  // 'this' becomes 'window' in a closure.
+
+    /**
+     * Compute and return the score for a match with e errors and x location.
+     * Accesses loc and pattern through being a closure.
+     * @param {number} e Number of errors in match.
+     * @param {number} x Location of match.
+     * @return {number} Overall score for match (0.0 = good, 1.0 = bad).
+     * @private
+     */
+    function match_bitapScore_(e, x) {
+      var accuracy = e / pattern.length;
+      var proximity = Math.abs(loc - x);
+      if (!dmp.Match_Distance) {
+        // Dodge divide by zero error.
+        return proximity ? 1.0 : accuracy;
+      }
+      return accuracy + (proximity / dmp.Match_Distance);
+    }
+
+    // Highest score beyond which we give up.
+    var score_threshold = this.Match_Threshold;
+    // Is there a nearby exact match? (speedup)
+    var best_loc = text.indexOf(pattern, loc);
+    if (best_loc != -1) {
+      score_threshold = Math.min(match_bitapScore_(0, best_loc), score_threshold);
+      // What about in the other direction? (speedup)
+      best_loc = text.lastIndexOf(pattern, loc + pattern.length);
+      if (best_loc != -1) {
+        score_threshold =
+            Math.min(match_bitapScore_(0, best_loc), score_threshold);
+      }
+    }
+
+    // Initialise the bit arrays.
+    var matchmask = 1 << (pattern.length - 1);
+    best_loc = -1;
+
+    var bin_min, bin_mid;
+    var bin_max = pattern.length + text.length;
+    var last_rd;
+    for (var d = 0; d < pattern.length; d++) {
+      // Scan for the best match; each iteration allows for one more error.
+      // Run a binary search to determine how far from 'loc' we can stray at this
+      // error level.
+      bin_min = 0;
+      bin_mid = bin_max;
+      while (bin_min < bin_mid) {
+        if (match_bitapScore_(d, loc + bin_mid) <= score_threshold) {
+          bin_min = bin_mid;
+        } else {
+          bin_max = bin_mid;
+        }
+        bin_mid = Math.floor((bin_max - bin_min) / 2 + bin_min);
+      }
+      // Use the result from this iteration as the maximum for the next.
+      bin_max = bin_mid;
+      var start = Math.max(1, loc - bin_mid + 1);
+      var finish = Math.min(loc + bin_mid, text.length) + pattern.length;
+
+      var rd = Array(finish + 2);
+      rd[finish + 1] = (1 << d) - 1;
+      for (var j = finish; j >= start; j--) {
+        // The alphabet (s) is a sparse hash, so the following line generates
+        // warnings.
+        var charMatch = s[text.charAt(j - 1)];
+        if (d === 0) {  // First pass: exact match.
+          rd[j] = ((rd[j + 1] << 1) | 1) & charMatch;
+        } else {  // Subsequent passes: fuzzy match.
+          rd[j] = ((rd[j + 1] << 1) | 1) & charMatch |
+                  (((last_rd[j + 1] | last_rd[j]) << 1) | 1) |
+                  last_rd[j + 1];
+        }
+        if (rd[j] & matchmask) {
+          var score = match_bitapScore_(d, j - 1);
+          // This match will almost certainly be better than any existing match.
+          // But check anyway.
+          if (score <= score_threshold) {
+            // Told you so.
+            score_threshold = score;
+            best_loc = j - 1;
+            if (best_loc > loc) {
+              // When passing loc, don't exceed our current distance from loc.
+              start = Math.max(1, 2 * loc - best_loc);
+            } else {
+              // Already passed loc, downhill from here on in.
+              break;
+            }
+          }
+        }
+      }
+      // No hope for a (better) match at greater error levels.
+      if (match_bitapScore_(d + 1, loc) > score_threshold) {
+        break;
+      }
+      last_rd = rd;
+    }
+    return best_loc;
+  };
+
+
+  /**
+   * Initialise the alphabet for the Bitap algorithm.
+   * @param {string} pattern The text to encode.
+   * @return {!Object} Hash of character locations.
+   * @private
+   */
+  diff_match_patch.prototype.match_alphabet_ = function(pattern) {
+    var s = {};
+    for (var i = 0; i < pattern.length; i++) {
+      s[pattern.charAt(i)] = 0;
+    }
+    for (var i = 0; i < pattern.length; i++) {
+      s[pattern.charAt(i)] |= 1 << (pattern.length - i - 1);
+    }
+    return s;
+  };
+
+
+  //  PATCH FUNCTIONS
+
+
+  /**
+   * Increase the context until it is unique,
+   * but don't let the pattern expand beyond Match_MaxBits.
+   * @param {!diff_match_patch.patch_obj} patch The patch to grow.
+   * @param {string} text Source text.
+   * @private
+   */
+  diff_match_patch.prototype.patch_addContext_ = function(patch, text) {
+    if (text.length == 0) {
+      return;
+    }
+    var pattern = text.substring(patch.start2, patch.start2 + patch.length1);
+    var padding = 0;
+
+    // Look for the first and last matches of pattern in text.  If two different
+    // matches are found, increase the pattern length.
+    while (text.indexOf(pattern) != text.lastIndexOf(pattern) &&
+           pattern.length < this.Match_MaxBits - this.Patch_Margin -
+           this.Patch_Margin) {
+      padding += this.Patch_Margin;
+      pattern = text.substring(patch.start2 - padding,
+                               patch.start2 + patch.length1 + padding);
+    }
+    // Add one chunk for good luck.
+    padding += this.Patch_Margin;
+
+    // Add the prefix.
+    var prefix = text.substring(patch.start2 - padding, patch.start2);
+    if (prefix) {
+      patch.diffs.unshift([DIFF_EQUAL, prefix]);
+    }
+    // Add the suffix.
+    var suffix = text.substring(patch.start2 + patch.length1,
+                                patch.start2 + patch.length1 + padding);
+    if (suffix) {
+      patch.diffs.push([DIFF_EQUAL, suffix]);
+    }
+
+    // Roll back the start points.
+    patch.start1 -= prefix.length;
+    patch.start2 -= prefix.length;
+    // Extend the lengths.
+    patch.length1 += prefix.length + suffix.length;
+    patch.length2 += prefix.length + suffix.length;
+  };
+
+
+  /**
+   * Compute a list of patches to turn text1 into text2.
+   * Use diffs if provided, otherwise compute it ourselves.
+   * There are four ways to call this function, depending on what data is
+   * available to the caller:
+   * Method 1:
+   * a = text1, b = text2
+   * Method 2:
+   * a = diffs
+   * Method 3 (optimal):
+   * a = text1, b = diffs
+   * Method 4 (deprecated, use method 3):
+   * a = text1, b = text2, c = diffs
+   *
+   * @param {string|!Array.<!diff_match_patch.Diff>} a text1 (methods 1,3,4) or
+   * Array of diff tuples for text1 to text2 (method 2).
+   * @param {string|!Array.<!diff_match_patch.Diff>} opt_b text2 (methods 1,4) or
+   * Array of diff tuples for text1 to text2 (method 3) or undefined (method 2).
+   * @param {string|!Array.<!diff_match_patch.Diff>} opt_c Array of diff tuples
+   * for text1 to text2 (method 4) or undefined (methods 1,2,3).
+   * @return {!Array.<!diff_match_patch.patch_obj>} Array of patch objects.
+   */
+  diff_match_patch.prototype.patch_make = function(a, opt_b, opt_c) {
+    var text1, diffs;
+    if (typeof a == 'string' && typeof opt_b == 'string' &&
+        typeof opt_c == 'undefined') {
+      // Method 1: text1, text2
+      // Compute diffs from text1 and text2.
+      text1 = /** @type {string} */(a);
+      diffs = this.diff_main(text1, /** @type {string} */(opt_b), true);
+      if (diffs.length > 2) {
+        this.diff_cleanupSemantic(diffs);
+        this.diff_cleanupEfficiency(diffs);
+      }
+    } else if (a && typeof a == 'object' && typeof opt_b == 'undefined' &&
+        typeof opt_c == 'undefined') {
+      // Method 2: diffs
+      // Compute text1 from diffs.
+      diffs = /** @type {!Array.<!diff_match_patch.Diff>} */(a);
+      text1 = this.diff_text1(diffs);
+    } else if (typeof a == 'string' && opt_b && typeof opt_b == 'object' &&
+        typeof opt_c == 'undefined') {
+      // Method 3: text1, diffs
+      text1 = /** @type {string} */(a);
+      diffs = /** @type {!Array.<!diff_match_patch.Diff>} */(opt_b);
+    } else if (typeof a == 'string' && typeof opt_b == 'string' &&
+        opt_c && typeof opt_c == 'object') {
+      // Method 4: text1, text2, diffs
+      // text2 is not used.
+      text1 = /** @type {string} */(a);
+      diffs = /** @type {!Array.<!diff_match_patch.Diff>} */(opt_c);
+    } else {
+      throw new Error('Unknown call format to patch_make.');
+    }
+
+    if (diffs.length === 0) {
+      return [];  // Get rid of the null case.
+    }
+    var patches = [];
+    var patch = new diff_match_patch.patch_obj();
+    var patchDiffLength = 0;  // Keeping our own length var is faster in JS.
+    var char_count1 = 0;  // Number of characters into the text1 string.
+    var char_count2 = 0;  // Number of characters into the text2 string.
+    // Start with text1 (prepatch_text) and apply the diffs until we arrive at
+    // text2 (postpatch_text).  We recreate the patches one by one to determine
+    // context info.
+    var prepatch_text = text1;
+    var postpatch_text = text1;
+    for (var x = 0; x < diffs.length; x++) {
+      var diff_type = diffs[x][0];
+      var diff_text = diffs[x][1];
+
+      if (!patchDiffLength && diff_type !== DIFF_EQUAL) {
+        // A new patch starts here.
+        patch.start1 = char_count1;
+        patch.start2 = char_count2;
+      }
+
+      switch (diff_type) {
+        case DIFF_INSERT:
+          patch.diffs[patchDiffLength++] = diffs[x];
+          patch.length2 += diff_text.length;
+          postpatch_text = postpatch_text.substring(0, char_count2) + diff_text +
+                           postpatch_text.substring(char_count2);
+          break;
+        case DIFF_DELETE:
+          patch.length1 += diff_text.length;
+          patch.diffs[patchDiffLength++] = diffs[x];
+          postpatch_text = postpatch_text.substring(0, char_count2) +
+                           postpatch_text.substring(char_count2 +
+                               diff_text.length);
+          break;
+        case DIFF_EQUAL:
+          if (diff_text.length <= 2 * this.Patch_Margin &&
+              patchDiffLength && diffs.length != x + 1) {
+            // Small equality inside a patch.
+            patch.diffs[patchDiffLength++] = diffs[x];
+            patch.length1 += diff_text.length;
+            patch.length2 += diff_text.length;
+          } else if (diff_text.length >= 2 * this.Patch_Margin) {
+            // Time for a new patch.
+            if (patchDiffLength) {
+              this.patch_addContext_(patch, prepatch_text);
+              patches.push(patch);
+              patch = new diff_match_patch.patch_obj();
+              patchDiffLength = 0;
+              // Unlike Unidiff, our patch lists have a rolling context.
+              // http://code.google.com/p/google-diff-match-patch/wiki/Unidiff
+              // Update prepatch text & pos to reflect the application of the
+              // just completed patch.
+              prepatch_text = postpatch_text;
+              char_count1 = char_count2;
+            }
+          }
+          break;
+      }
+
+      // Update the current character count.
+      if (diff_type !== DIFF_INSERT) {
+        char_count1 += diff_text.length;
+      }
+      if (diff_type !== DIFF_DELETE) {
+        char_count2 += diff_text.length;
+      }
+    }
+    // Pick up the leftover patch if not empty.
+    if (patchDiffLength) {
+      this.patch_addContext_(patch, prepatch_text);
+      patches.push(patch);
+    }
+
+    return patches;
+  };
+
+
+  /**
+   * Given an array of patches, return another array that is identical.
+   * @param {!Array.<!diff_match_patch.patch_obj>} patches Array of patch objects.
+   * @return {!Array.<!diff_match_patch.patch_obj>} Array of patch objects.
+   */
+  diff_match_patch.prototype.patch_deepCopy = function(patches) {
+    // Making deep copies is hard in JavaScript.
+    var patchesCopy = [];
+    for (var x = 0; x < patches.length; x++) {
+      var patch = patches[x];
+      var patchCopy = new diff_match_patch.patch_obj();
+      patchCopy.diffs = [];
+      for (var y = 0; y < patch.diffs.length; y++) {
+        patchCopy.diffs[y] = patch.diffs[y].slice();
+      }
+      patchCopy.start1 = patch.start1;
+      patchCopy.start2 = patch.start2;
+      patchCopy.length1 = patch.length1;
+      patchCopy.length2 = patch.length2;
+      patchesCopy[x] = patchCopy;
+    }
+    return patchesCopy;
+  };
+
+
+  /**
+   * Merge a set of patches onto the text.  Return a patched text, as well
+   * as a list of true/false values indicating which patches were applied.
+   * @param {!Array.<!diff_match_patch.patch_obj>} patches Array of patch objects.
+   * @param {string} text Old text.
+   * @return {!Array.<string|!Array.<boolean>>} Two element Array, containing the
+   *      new text and an array of boolean values.
+   */
+  diff_match_patch.prototype.patch_apply = function(patches, text) {
+    if (patches.length == 0) {
+      return [text, []];
+    }
+
+    // Deep copy the patches so that no changes are made to originals.
+    patches = this.patch_deepCopy(patches);
+
+    var nullPadding = this.patch_addPadding(patches);
+    text = nullPadding + text + nullPadding;
+
+    this.patch_splitMax(patches);
+    // delta keeps track of the offset between the expected and actual location
+    // of the previous patch.  If there are patches expected at positions 10 and
+    // 20, but the first patch was found at 12, delta is 2 and the second patch
+    // has an effective expected position of 22.
+    var delta = 0;
+    var results = [];
+    for (var x = 0; x < patches.length; x++) {
+      var expected_loc = patches[x].start2 + delta;
+      var text1 = this.diff_text1(patches[x].diffs);
+      var start_loc;
+      var end_loc = -1;
+      if (text1.length > this.Match_MaxBits) {
+        // patch_splitMax will only provide an oversized pattern in the case of
+        // a monster delete.
+        start_loc = this.match_main(text, text1.substring(0, this.Match_MaxBits),
+                                    expected_loc);
+        if (start_loc != -1) {
+          end_loc = this.match_main(text,
+              text1.substring(text1.length - this.Match_MaxBits),
+              expected_loc + text1.length - this.Match_MaxBits);
+          if (end_loc == -1 || start_loc >= end_loc) {
+            // Can't find valid trailing context.  Drop this patch.
+            start_loc = -1;
+          }
+        }
+      } else {
+        start_loc = this.match_main(text, text1, expected_loc);
+      }
+      if (start_loc == -1) {
+        // No match found.  :(
+        results[x] = false;
+        // Subtract the delta for this failed patch from subsequent patches.
+        delta -= patches[x].length2 - patches[x].length1;
+      } else {
+        // Found a match.  :)
+        results[x] = true;
+        delta = start_loc - expected_loc;
+        var text2;
+        if (end_loc == -1) {
+          text2 = text.substring(start_loc, start_loc + text1.length);
+        } else {
+          text2 = text.substring(start_loc, end_loc + this.Match_MaxBits);
+        }
+        if (text1 == text2) {
+          // Perfect match, just shove the replacement text in.
+          text = text.substring(0, start_loc) +
+                 this.diff_text2(patches[x].diffs) +
+                 text.substring(start_loc + text1.length);
+        } else {
+          // Imperfect match.  Run a diff to get a framework of equivalent
+          // indices.
+          var diffs = this.diff_main(text1, text2, false);
+          if (text1.length > this.Match_MaxBits &&
+              this.diff_levenshtein(diffs) / text1.length >
+              this.Patch_DeleteThreshold) {
+            // The end points match, but the content is unacceptably bad.
+            results[x] = false;
+          } else {
+            this.diff_cleanupSemanticLossless(diffs);
+            var index1 = 0;
+            var index2;
+            for (var y = 0; y < patches[x].diffs.length; y++) {
+              var mod = patches[x].diffs[y];
+              if (mod[0] !== DIFF_EQUAL) {
+                index2 = this.diff_xIndex(diffs, index1);
+              }
+              if (mod[0] === DIFF_INSERT) {  // Insertion
+                text = text.substring(0, start_loc + index2) + mod[1] +
+                       text.substring(start_loc + index2);
+              } else if (mod[0] === DIFF_DELETE) {  // Deletion
+                text = text.substring(0, start_loc + index2) +
+                       text.substring(start_loc + this.diff_xIndex(diffs,
+                           index1 + mod[1].length));
+              }
+              if (mod[0] !== DIFF_DELETE) {
+                index1 += mod[1].length;
+              }
+            }
+          }
+        }
+      }
+    }
+    // Strip the padding off.
+    text = text.substring(nullPadding.length, text.length - nullPadding.length);
+    return [text, results];
+  };
+
+
+  /**
+   * Add some padding on text start and end so that edges can match something.
+   * Intended to be called only from within patch_apply.
+   * @param {!Array.<!diff_match_patch.patch_obj>} patches Array of patch objects.
+   * @return {string} The padding string added to each side.
+   */
+  diff_match_patch.prototype.patch_addPadding = function(patches) {
+    var paddingLength = this.Patch_Margin;
+    var nullPadding = '';
+    for (var x = 1; x <= paddingLength; x++) {
+      nullPadding += String.fromCharCode(x);
+    }
+
+    // Bump all the patches forward.
+    for (var x = 0; x < patches.length; x++) {
+      patches[x].start1 += paddingLength;
+      patches[x].start2 += paddingLength;
+    }
+
+    // Add some padding on start of first diff.
+    var patch = patches[0];
+    var diffs = patch.diffs;
+    if (diffs.length == 0 || diffs[0][0] != DIFF_EQUAL) {
+      // Add nullPadding equality.
+      diffs.unshift([DIFF_EQUAL, nullPadding]);
+      patch.start1 -= paddingLength;  // Should be 0.
+      patch.start2 -= paddingLength;  // Should be 0.
+      patch.length1 += paddingLength;
+      patch.length2 += paddingLength;
+    } else if (paddingLength > diffs[0][1].length) {
+      // Grow first equality.
+      var extraLength = paddingLength - diffs[0][1].length;
+      diffs[0][1] = nullPadding.substring(diffs[0][1].length) + diffs[0][1];
+      patch.start1 -= extraLength;
+      patch.start2 -= extraLength;
+      patch.length1 += extraLength;
+      patch.length2 += extraLength;
+    }
+
+    // Add some padding on end of last diff.
+    patch = patches[patches.length - 1];
+    diffs = patch.diffs;
+    if (diffs.length == 0 || diffs[diffs.length - 1][0] != DIFF_EQUAL) {
+      // Add nullPadding equality.
+      diffs.push([DIFF_EQUAL, nullPadding]);
+      patch.length1 += paddingLength;
+      patch.length2 += paddingLength;
+    } else if (paddingLength > diffs[diffs.length - 1][1].length) {
+      // Grow last equality.
+      var extraLength = paddingLength - diffs[diffs.length - 1][1].length;
+      diffs[diffs.length - 1][1] += nullPadding.substring(0, extraLength);
+      patch.length1 += extraLength;
+      patch.length2 += extraLength;
+    }
+
+    return nullPadding;
+  };
+
+
+  /**
+   * Look through the patches and break up any which are longer than the maximum
+   * limit of the match algorithm.
+   * Intended to be called only from within patch_apply.
+   * @param {!Array.<!diff_match_patch.patch_obj>} patches Array of patch objects.
+   */
+  diff_match_patch.prototype.patch_splitMax = function(patches) {
+    var patch_size = this.Match_MaxBits;
+    for (var x = 0; x < patches.length; x++) {
+      if (patches[x].length1 > patch_size) {
+        var bigpatch = patches[x];
+        // Remove the big old patch.
+        patches.splice(x--, 1);
+        var start1 = bigpatch.start1;
+        var start2 = bigpatch.start2;
+        var precontext = '';
+        while (bigpatch.diffs.length !== 0) {
+          // Create one of several smaller patches.
+          var patch = new diff_match_patch.patch_obj();
+          var empty = true;
+          patch.start1 = start1 - precontext.length;
+          patch.start2 = start2 - precontext.length;
+          if (precontext !== '') {
+            patch.length1 = patch.length2 = precontext.length;
+            patch.diffs.push([DIFF_EQUAL, precontext]);
+          }
+          while (bigpatch.diffs.length !== 0 &&
+                 patch.length1 < patch_size - this.Patch_Margin) {
+            var diff_type = bigpatch.diffs[0][0];
+            var diff_text = bigpatch.diffs[0][1];
+            if (diff_type === DIFF_INSERT) {
+              // Insertions are harmless.
+              patch.length2 += diff_text.length;
+              start2 += diff_text.length;
+              patch.diffs.push(bigpatch.diffs.shift());
+              empty = false;
+            } else if (diff_type === DIFF_DELETE && patch.diffs.length == 1 &&
+                       patch.diffs[0][0] == DIFF_EQUAL &&
+                       diff_text.length > 2 * patch_size) {
+              // This is a large deletion.  Let it pass in one chunk.
+              patch.length1 += diff_text.length;
+              start1 += diff_text.length;
+              empty = false;
+              patch.diffs.push([diff_type, diff_text]);
+              bigpatch.diffs.shift();
+            } else {
+              // Deletion or equality.  Only take as much as we can stomach.
+              diff_text = diff_text.substring(0,
+                  patch_size - patch.length1 - this.Patch_Margin);
+              patch.length1 += diff_text.length;
+              start1 += diff_text.length;
+              if (diff_type === DIFF_EQUAL) {
+                patch.length2 += diff_text.length;
+                start2 += diff_text.length;
+              } else {
+                empty = false;
+              }
+              patch.diffs.push([diff_type, diff_text]);
+              if (diff_text == bigpatch.diffs[0][1]) {
+                bigpatch.diffs.shift();
+              } else {
+                bigpatch.diffs[0][1] =
+                    bigpatch.diffs[0][1].substring(diff_text.length);
+              }
+            }
+          }
+          // Compute the head context for the next patch.
+          precontext = this.diff_text2(patch.diffs);
+          precontext =
+              precontext.substring(precontext.length - this.Patch_Margin);
+          // Append the end context for this patch.
+          var postcontext = this.diff_text1(bigpatch.diffs)
+                                .substring(0, this.Patch_Margin);
+          if (postcontext !== '') {
+            patch.length1 += postcontext.length;
+            patch.length2 += postcontext.length;
+            if (patch.diffs.length !== 0 &&
+                patch.diffs[patch.diffs.length - 1][0] === DIFF_EQUAL) {
+              patch.diffs[patch.diffs.length - 1][1] += postcontext;
+            } else {
+              patch.diffs.push([DIFF_EQUAL, postcontext]);
+            }
+          }
+          if (!empty) {
+            patches.splice(++x, 0, patch);
+          }
+        }
+      }
+    }
+  };
+
+
+  /**
+   * Take a list of patches and return a textual representation.
+   * @param {!Array.<!diff_match_patch.patch_obj>} patches Array of patch objects.
+   * @return {string} Text representation of patches.
+   */
+  diff_match_patch.prototype.patch_toText = function(patches) {
+    var text = [];
+    for (var x = 0; x < patches.length; x++) {
+      text[x] = patches[x];
+    }
+    return text.join('');
+  };
+
+
+  /**
+   * Parse a textual representation of patches and return a list of patch objects.
+   * @param {string} textline Text representation of patches.
+   * @return {!Array.<!diff_match_patch.patch_obj>} Array of patch objects.
+   * @throws {!Error} If invalid input.
+   */
+  diff_match_patch.prototype.patch_fromText = function(textline) {
+    var patches = [];
+    if (!textline) {
+      return patches;
+    }
+    var text = textline.split('\n');
+    var textPointer = 0;
+    var patchHeader = /^@@ -(\d+),?(\d*) \+(\d+),?(\d*) @@$/;
+    while (textPointer < text.length) {
+      var m = text[textPointer].match(patchHeader);
+      if (!m) {
+        throw new Error('Invalid patch string: ' + text[textPointer]);
+      }
+      var patch = new diff_match_patch.patch_obj();
+      patches.push(patch);
+      patch.start1 = parseInt(m[1], 10);
+      if (m[2] === '') {
+        patch.start1--;
+        patch.length1 = 1;
+      } else if (m[2] == '0') {
+        patch.length1 = 0;
+      } else {
+        patch.start1--;
+        patch.length1 = parseInt(m[2], 10);
+      }
+
+      patch.start2 = parseInt(m[3], 10);
+      if (m[4] === '') {
+        patch.start2--;
+        patch.length2 = 1;
+      } else if (m[4] == '0') {
+        patch.length2 = 0;
+      } else {
+        patch.start2--;
+        patch.length2 = parseInt(m[4], 10);
+      }
+      textPointer++;
+
+      while (textPointer < text.length) {
+        var sign = text[textPointer].charAt(0);
+        try {
+          var line = decodeURI(text[textPointer].substring(1));
+        } catch (ex) {
+          // Malformed URI sequence.
+          throw new Error('Illegal escape in patch_fromText: ' + line);
+        }
+        if (sign == '-') {
+          // Deletion.
+          patch.diffs.push([DIFF_DELETE, line]);
+        } else if (sign == '+') {
+          // Insertion.
+          patch.diffs.push([DIFF_INSERT, line]);
+        } else if (sign == ' ') {
+          // Minor equality.
+          patch.diffs.push([DIFF_EQUAL, line]);
+        } else if (sign == '@') {
+          // Start of next patch.
+          break;
+        } else if (sign === '') {
+          // Blank line?  Whatever.
+        } else {
+          // WTF?
+          throw new Error('Invalid patch mode "' + sign + '" in: ' + line);
+        }
+        textPointer++;
+      }
+    }
+    return patches;
+  };
+
+
+  /**
+   * Class representing one patch operation.
+   * @constructor
+   */
+  diff_match_patch.patch_obj = function() {
+    /** @type {!Array.<!diff_match_patch.Diff>} */
+    this.diffs = [];
+    /** @type {?number} */
+    this.start1 = null;
+    /** @type {?number} */
+    this.start2 = null;
+    /** @type {number} */
+    this.length1 = 0;
+    /** @type {number} */
+    this.length2 = 0;
+  };
+
+
+  /**
+   * Emmulate GNU diff's format.
+   * Header: @@ -382,8 +481,9 @@
+   * Indicies are printed as 1-based, not 0-based.
+   * @return {string} The GNU diff string.
+   */
+  diff_match_patch.patch_obj.prototype.toString = function() {
+    var coords1, coords2;
+    if (this.length1 === 0) {
+      coords1 = this.start1 + ',0';
+    } else if (this.length1 == 1) {
+      coords1 = this.start1 + 1;
+    } else {
+      coords1 = (this.start1 + 1) + ',' + this.length1;
+    }
+    if (this.length2 === 0) {
+      coords2 = this.start2 + ',0';
+    } else if (this.length2 == 1) {
+      coords2 = this.start2 + 1;
+    } else {
+      coords2 = (this.start2 + 1) + ',' + this.length2;
+    }
+    var text = ['@@ -' + coords1 + ' +' + coords2 + ' @@\n'];
+    var op;
+    // Escape the body of the patch with %xx notation.
+    for (var x = 0; x < this.diffs.length; x++) {
+      switch (this.diffs[x][0]) {
+        case DIFF_INSERT:
+          op = '+';
+          break;
+        case DIFF_DELETE:
+          op = '-';
+          break;
+        case DIFF_EQUAL:
+          op = ' ';
+          break;
+      }
+      text[x + 1] = op + encodeURI(this.diffs[x][1]) + '\n';
+    }
+    return text.join('').replace(/%20/g, ' ');
+  };
+
+
+  // Export these global variables so that they survive Google's JS compiler.
+  // In a browser, 'this' will be 'window'.
+  // In node.js 'this' will be a global object.
+  this['diff_match_patch'] = diff_match_patch;
+  this['DIFF_DELETE'] = DIFF_DELETE;
+  this['DIFF_INSERT'] = DIFF_INSERT;
+  this['DIFF_EQUAL'] = DIFF_EQUAL;
+
+
+  },{}],3:[function(require,module,exports){
+
+  var isArray = (typeof Array.isArray === 'function') ?
+    // use native function
+    Array.isArray :
+    // use instanceof operator
+    function(a) {
+      return a instanceof Array;
+    };
+
+  function cloneRegExp(re) {
+    var regexMatch = /^\/(.*)\/([gimyu]*)$/.exec(re.toString());
+    return new RegExp(regexMatch[1], regexMatch[2]);
+  }
+
+  function clone(arg) {
+    if (typeof arg !== 'object') {
+      return arg;
+    }
+    if (arg === null) {
+      return null;
+    }
+    if (isArray(arg)) {
+      return arg.map(clone);
+    }
+    if (arg instanceof Date) {
+      return new Date(arg.getTime());
+    }
+    if (arg instanceof RegExp) {
+      return cloneRegExp(arg);
+    }
+    var cloned = {};
+    for (var name in arg) {
+      if (Object.prototype.hasOwnProperty.call(arg, name)) {
+        cloned[name] = clone(arg[name]);
+      }
+    }
+    return cloned;
+  }
+
+  module.exports = clone;
+
+  },{}],4:[function(require,module,exports){
+
+  var Pipe = require('../pipe').Pipe;
+
+  var Context = function Context(){
+  };
+
+  Context.prototype.setResult = function(result) {
+    this.result = result;
+    this.hasResult = true;
+    return this;
+  };
+
+  Context.prototype.exit = function() {
+    this.exiting = true;
+    return this;
+  };
+
+  Context.prototype.switchTo = function(next, pipe) {
+    if (typeof next === 'string' || next instanceof Pipe) {
+      this.nextPipe = next;
+    } else {
+      this.next = next;
+      if (pipe) {
+        this.nextPipe = pipe;
+      }
+    }
+    return this;
+  };
+
+  Context.prototype.push = function(child, name) {
+    child.parent = this;
+    if (typeof name !== 'undefined') {
+      child.childName = name;
+    }
+    child.root = this.root || this;
+    child.options = child.options || this.options;
+    if (!this.children) {
+      this.children = [child];
+      this.nextAfterChildren = this.next || null;
+      this.next = child;
+    } else {
+      this.children[this.children.length - 1].next = child;
+      this.children.push(child);
+    }
+    child.next = this;
+    return this;
+  };
+
+  exports.Context = Context;
+
+  },{"../pipe":18}],5:[function(require,module,exports){
+  var Context = require('./context').Context;
+  var defaultClone = require('../clone');
+
+  var DiffContext = function DiffContext(left, right) {
+    this.left = left;
+    this.right = right;
+    this.pipe = 'diff';
+  };
+
+  DiffContext.prototype = new Context();
+
+  DiffContext.prototype.setResult = function(result) {
+    if (this.options.cloneDiffValues && typeof result === 'object') {
+      var clone = typeof this.options.cloneDiffValues === 'function' ?
+        this.options.cloneDiffValues : defaultClone;
+      if (typeof result[0] === 'object') {
+        result[0] = clone(result[0]);
+      }
+      if (typeof result[1] === 'object') {
+        result[1] = clone(result[1]);
+      }
+    }
+    return Context.prototype.setResult.apply(this, arguments);
+  };
+
+  exports.DiffContext = DiffContext;
+
+  },{"../clone":3,"./context":4}],6:[function(require,module,exports){
+  var Context = require('./context').Context;
+
+  var PatchContext = function PatchContext(left, delta) {
+    this.left = left;
+    this.delta = delta;
+    this.pipe = 'patch';
+  };
+
+  PatchContext.prototype = new Context();
+
+  exports.PatchContext = PatchContext;
+
+  },{"./context":4}],7:[function(require,module,exports){
+  var Context = require('./context').Context;
+
+  var ReverseContext = function ReverseContext(delta) {
+    this.delta = delta;
+    this.pipe = 'reverse';
+  };
+
+  ReverseContext.prototype = new Context();
+
+  exports.ReverseContext = ReverseContext;
+
+  },{"./context":4}],8:[function(require,module,exports){
+  // use as 2nd parameter for JSON.parse to revive Date instances
+  module.exports = function dateReviver(key, value) {
+    var parts;
+    if (typeof value === 'string') {
+      parts = /^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.(\d*))?(Z|([+\-])(\d{2}):(\d{2}))$/.exec(value);
+      if (parts) {
+        return new Date(Date.UTC(+parts[1], +parts[2] - 1, +parts[3], +parts[4], +parts[5], +parts[6], +(parts[7] || 0)));
+      }
+    }
+    return value;
+  };
+
+  },{}],9:[function(require,module,exports){
+  var Processor = require('./processor').Processor;
+  var Pipe = require('./pipe').Pipe;
+  var DiffContext = require('./contexts/diff').DiffContext;
+  var PatchContext = require('./contexts/patch').PatchContext;
+  var ReverseContext = require('./contexts/reverse').ReverseContext;
+
+  var clone = require('./clone');
+
+  var trivial = require('./filters/trivial');
+  var nested = require('./filters/nested');
+  var arrays = require('./filters/arrays');
+  var dates = require('./filters/dates');
+  var texts = require('./filters/texts');
+
+  var DiffPatcher = function DiffPatcher(options) {
+    this.processor = new Processor(options);
+    this.processor.pipe(new Pipe('diff').append(
+      nested.collectChildrenDiffFilter,
+      trivial.diffFilter,
+      dates.diffFilter,
+      texts.diffFilter,
+      nested.objectsDiffFilter,
+      arrays.diffFilter
+    ).shouldHaveResult());
+    this.processor.pipe(new Pipe('patch').append(
+      nested.collectChildrenPatchFilter,
+      arrays.collectChildrenPatchFilter,
+      trivial.patchFilter,
+      texts.patchFilter,
+      nested.patchFilter,
+      arrays.patchFilter
+    ).shouldHaveResult());
+    this.processor.pipe(new Pipe('reverse').append(
+      nested.collectChildrenReverseFilter,
+      arrays.collectChildrenReverseFilter,
+      trivial.reverseFilter,
+      texts.reverseFilter,
+      nested.reverseFilter,
+      arrays.reverseFilter
+    ).shouldHaveResult());
+  };
+
+  DiffPatcher.prototype.options = function() {
+    return this.processor.options.apply(this.processor, arguments);
+  };
+
+  DiffPatcher.prototype.diff = function(left, right) {
+    return this.processor.process(new DiffContext(left, right));
+  };
+
+  DiffPatcher.prototype.patch = function(left, delta) {
+    return this.processor.process(new PatchContext(left, delta));
+  };
+
+  DiffPatcher.prototype.reverse = function(delta) {
+    return this.processor.process(new ReverseContext(delta));
+  };
+
+  DiffPatcher.prototype.unpatch = function(right, delta) {
+    return this.patch(right, this.reverse(delta));
+  };
+
+  DiffPatcher.prototype.clone = function(value) {
+    return clone(value);
+  };
+
+  exports.DiffPatcher = DiffPatcher;
+
+  },{"./clone":3,"./contexts/diff":5,"./contexts/patch":6,"./contexts/reverse":7,"./filters/arrays":11,"./filters/dates":12,"./filters/nested":14,"./filters/texts":15,"./filters/trivial":16,"./pipe":18,"./processor":19}],10:[function(require,module,exports){
+
+  exports.isBrowser = typeof window !== 'undefined';
+
+  },{}],11:[function(require,module,exports){
+  var DiffContext = require('../contexts/diff').DiffContext;
+  var PatchContext = require('../contexts/patch').PatchContext;
+  var ReverseContext = require('../contexts/reverse').ReverseContext;
+
+  var lcs = require('./lcs');
+
+  var ARRAY_MOVE = 3;
+
+  var isArray = (typeof Array.isArray === 'function') ?
+    // use native function
+    Array.isArray :
+    // use instanceof operator
+    function(a) {
+      return a instanceof Array;
+    };
+
+  var arrayIndexOf = typeof Array.prototype.indexOf === 'function' ?
+    function(array, item) {
+      return array.indexOf(item);
+    } : function(array, item) {
+      var length = array.length;
+      for (var i = 0; i < length; i++) {
+        if (array[i] === item) {
+          return i;
+        }
+      }
+      return -1;
+    };
+
+  function arraysHaveMatchByRef(array1, array2, len1, len2) {
+    for (var index1 = 0; index1 < len1; index1++) {
+      var val1 = array1[index1];
+      for (var index2 = 0; index2 < len2; index2++) {
+        var val2 = array2[index2];
+        if (index1 !== index2 && val1 === val2) {
+          return true;
+        }
+      }
+    }
+  }
+
+  function matchItems(array1, array2, index1, index2, context) {
+    var value1 = array1[index1];
+    var value2 = array2[index2];
+    if (value1 === value2) {
+      return true;
+    }
+    if (typeof value1 !== 'object' || typeof value2 !== 'object') {
+      return false;
+    }
+    var objectHash = context.objectHash;
+    if (!objectHash) {
+      // no way to match objects was provided, try match by position
+      return context.matchByPosition && index1 === index2;
+    }
+    var hash1;
+    var hash2;
+    if (typeof index1 === 'number') {
+      context.hashCache1 = context.hashCache1 || [];
+      hash1 = context.hashCache1[index1];
+      if (typeof hash1 === 'undefined') {
+        context.hashCache1[index1] = hash1 = objectHash(value1, index1);
+      }
+    } else {
+      hash1 = objectHash(value1);
+    }
+    if (typeof hash1 === 'undefined') {
+      return false;
+    }
+    if (typeof index2 === 'number') {
+      context.hashCache2 = context.hashCache2 || [];
+      hash2 = context.hashCache2[index2];
+      if (typeof hash2 === 'undefined') {
+        context.hashCache2[index2] = hash2 = objectHash(value2, index2);
+      }
+    } else {
+      hash2 = objectHash(value2);
+    }
+    if (typeof hash2 === 'undefined') {
+      return false;
+    }
+    return hash1 === hash2;
+  }
+
+  var diffFilter = function arraysDiffFilter(context) {
+    if (!context.leftIsArray) {
+      return;
+    }
+
+    var matchContext = {
+      objectHash: context.options && context.options.objectHash,
+      matchByPosition: context.options && context.options.matchByPosition
+    };
+    var commonHead = 0;
+    var commonTail = 0;
+    var index;
+    var index1;
+    var index2;
+    var array1 = context.left;
+    var array2 = context.right;
+    var len1 = array1.length;
+    var len2 = array2.length;
+
+    var child;
+
+    if (len1 > 0 && len2 > 0 && !matchContext.objectHash &&
+      typeof matchContext.matchByPosition !== 'boolean') {
+      matchContext.matchByPosition = !arraysHaveMatchByRef(array1, array2, len1, len2);
+    }
+
+    // separate common head
+    while (commonHead < len1 && commonHead < len2 &&
+      matchItems(array1, array2, commonHead, commonHead, matchContext)) {
+      index = commonHead;
+      child = new DiffContext(context.left[index], context.right[index]);
+      context.push(child, index);
+      commonHead++;
+    }
+    // separate common tail
+    while (commonTail + commonHead < len1 && commonTail + commonHead < len2 &&
+      matchItems(array1, array2, len1 - 1 - commonTail, len2 - 1 - commonTail, matchContext)) {
+      index1 = len1 - 1 - commonTail;
+      index2 = len2 - 1 - commonTail;
+      child = new DiffContext(context.left[index1], context.right[index2]);
+      context.push(child, index2);
+      commonTail++;
+    }
+    var result;
+    if (commonHead + commonTail === len1) {
+      if (len1 === len2) {
+        // arrays are identical
+        context.setResult(undefined).exit();
+        return;
+      }
+      // trivial case, a block (1 or more consecutive items) was added
+      result = result || {
+        _t: 'a'
+      };
+      for (index = commonHead; index < len2 - commonTail; index++) {
+        result[index] = [array2[index]];
+      }
+      context.setResult(result).exit();
+      return;
+    }
+    if (commonHead + commonTail === len2) {
+      // trivial case, a block (1 or more consecutive items) was removed
+      result = result || {
+        _t: 'a'
+      };
+      for (index = commonHead; index < len1 - commonTail; index++) {
+        result['_' + index] = [array1[index], 0, 0];
+      }
+      context.setResult(result).exit();
+      return;
+    }
+    // reset hash cache
+    delete matchContext.hashCache1;
+    delete matchContext.hashCache2;
+
+    // diff is not trivial, find the LCS (Longest Common Subsequence)
+    var trimmed1 = array1.slice(commonHead, len1 - commonTail);
+    var trimmed2 = array2.slice(commonHead, len2 - commonTail);
+    var seq = lcs.get(
+      trimmed1, trimmed2,
+      matchItems,
+      matchContext
+    );
+    var removedItems = [];
+    result = result || {
+      _t: 'a'
+    };
+    for (index = commonHead; index < len1 - commonTail; index++) {
+      if (arrayIndexOf(seq.indices1, index - commonHead) < 0) {
+        // removed
+        result['_' + index] = [array1[index], 0, 0];
+        removedItems.push(index);
+      }
+    }
+
+    var detectMove = true;
+    if (context.options && context.options.arrays && context.options.arrays.detectMove === false) {
+      detectMove = false;
+    }
+    var includeValueOnMove = false;
+    if (context.options && context.options.arrays && context.options.arrays.includeValueOnMove) {
+      includeValueOnMove = true;
+    }
+
+    var removedItemsLength = removedItems.length;
+    for (index = commonHead; index < len2 - commonTail; index++) {
+      var indexOnArray2 = arrayIndexOf(seq.indices2, index - commonHead);
+      if (indexOnArray2 < 0) {
+        // added, try to match with a removed item and register as position move
+        var isMove = false;
+        if (detectMove && removedItemsLength > 0) {
+          for (var removeItemIndex1 = 0; removeItemIndex1 < removedItemsLength; removeItemIndex1++) {
+            index1 = removedItems[removeItemIndex1];
+            if (matchItems(trimmed1, trimmed2, index1 - commonHead,
+              index - commonHead, matchContext)) {
+              // store position move as: [originalValue, newPosition, ARRAY_MOVE]
+              result['_' + index1].splice(1, 2, index, ARRAY_MOVE);
+              if (!includeValueOnMove) {
+                // don't include moved value on diff, to save bytes
+                result['_' + index1][0] = '';
+              }
+
+              index2 = index;
+              child = new DiffContext(context.left[index1], context.right[index2]);
+              context.push(child, index2);
+              removedItems.splice(removeItemIndex1, 1);
+              isMove = true;
+              break;
+            }
+          }
+        }
+        if (!isMove) {
+          // added
+          result[index] = [array2[index]];
+        }
+      } else {
+        // match, do inner diff
+        index1 = seq.indices1[indexOnArray2] + commonHead;
+        index2 = seq.indices2[indexOnArray2] + commonHead;
+        child = new DiffContext(context.left[index1], context.right[index2]);
+        context.push(child, index2);
+      }
+    }
+
+    context.setResult(result).exit();
+
+  };
+  diffFilter.filterName = 'arrays';
+
+  var compare = {
+    numerically: function(a, b) {
+      return a - b;
+    },
+    numericallyBy: function(name) {
+      return function(a, b) {
+        return a[name] - b[name];
+      };
+    }
+  };
+
+  var patchFilter = function nestedPatchFilter(context) {
+    if (!context.nested) {
+      return;
+    }
+    if (context.delta._t !== 'a') {
+      return;
+    }
+    var index, index1;
+
+    var delta = context.delta;
+    var array = context.left;
+
+    // first, separate removals, insertions and modifications
+    var toRemove = [];
+    var toInsert = [];
+    var toModify = [];
+    for (index in delta) {
+      if (index !== '_t') {
+        if (index[0] === '_') {
+          // removed item from original array
+          if (delta[index][2] === 0 || delta[index][2] === ARRAY_MOVE) {
+            toRemove.push(parseInt(index.slice(1), 10));
+          } else {
+            throw new Error('only removal or move can be applied at original array indices' +
+              ', invalid diff type: ' + delta[index][2]);
+          }
+        } else {
+          if (delta[index].length === 1) {
+            // added item at new array
+            toInsert.push({
+              index: parseInt(index, 10),
+              value: delta[index][0]
+            });
+          } else {
+            // modified item at new array
+            toModify.push({
+              index: parseInt(index, 10),
+              delta: delta[index]
+            });
+          }
+        }
+      }
+    }
+
+    // remove items, in reverse order to avoid sawing our own floor
+    toRemove = toRemove.sort(compare.numerically);
+    for (index = toRemove.length - 1; index >= 0; index--) {
+      index1 = toRemove[index];
+      var indexDiff = delta['_' + index1];
+      var removedValue = array.splice(index1, 1)[0];
+      if (indexDiff[2] === ARRAY_MOVE) {
+        // reinsert later
+        toInsert.push({
+          index: indexDiff[1],
+          value: removedValue
+        });
+      }
+    }
+
+    // insert items, in reverse order to avoid moving our own floor
+    toInsert = toInsert.sort(compare.numericallyBy('index'));
+    var toInsertLength = toInsert.length;
+    for (index = 0; index < toInsertLength; index++) {
+      var insertion = toInsert[index];
+      array.splice(insertion.index, 0, insertion.value);
+    }
+
+    // apply modifications
+    var toModifyLength = toModify.length;
+    var child;
+    if (toModifyLength > 0) {
+      for (index = 0; index < toModifyLength; index++) {
+        var modification = toModify[index];
+        child = new PatchContext(context.left[modification.index], modification.delta);
+        context.push(child, modification.index);
+      }
+    }
+
+    if (!context.children) {
+      context.setResult(context.left).exit();
+      return;
+    }
+    context.exit();
+  };
+  patchFilter.filterName = 'arrays';
+
+  var collectChildrenPatchFilter = function collectChildrenPatchFilter(context) {
+    if (!context || !context.children) {
+      return;
+    }
+    if (context.delta._t !== 'a') {
+      return;
+    }
+    var length = context.children.length;
+    var child;
+    for (var index = 0; index < length; index++) {
+      child = context.children[index];
+      context.left[child.childName] = child.result;
+    }
+    context.setResult(context.left).exit();
+  };
+  collectChildrenPatchFilter.filterName = 'arraysCollectChildren';
+
+  var reverseFilter = function arraysReverseFilter(context) {
+    if (!context.nested) {
+      if (context.delta[2] === ARRAY_MOVE) {
+        context.newName = '_' + context.delta[1];
+        context.setResult([context.delta[0], parseInt(context.childName.substr(1), 10), ARRAY_MOVE]).exit();
+      }
+      return;
+    }
+    if (context.delta._t !== 'a') {
+      return;
+    }
+    var name, child;
+    for (name in context.delta) {
+      if (name === '_t') {
+        continue;
+      }
+      child = new ReverseContext(context.delta[name]);
+      context.push(child, name);
+    }
+    context.exit();
+  };
+  reverseFilter.filterName = 'arrays';
+
+  var reverseArrayDeltaIndex = function(delta, index, itemDelta) {
+    if (typeof index === 'string' && index[0] === '_') {
+      return parseInt(index.substr(1), 10);
+    } else if (isArray(itemDelta) && itemDelta[2] === 0) {
+      return '_' + index;
+    }
+
+    var reverseIndex = +index;
+    for (var deltaIndex in delta) {
+      var deltaItem = delta[deltaIndex];
+      if (isArray(deltaItem)) {
+        if (deltaItem[2] === ARRAY_MOVE) {
+          var moveFromIndex = parseInt(deltaIndex.substr(1), 10);
+          var moveToIndex = deltaItem[1];
+          if (moveToIndex === +index) {
+            return moveFromIndex;
+          }
+          if (moveFromIndex <= reverseIndex && moveToIndex > reverseIndex) {
+            reverseIndex++;
+          } else if (moveFromIndex >= reverseIndex && moveToIndex < reverseIndex) {
+            reverseIndex--;
+          }
+        } else if (deltaItem[2] === 0) {
+          var deleteIndex = parseInt(deltaIndex.substr(1), 10);
+          if (deleteIndex <= reverseIndex) {
+            reverseIndex++;
+          }
+        } else if (deltaItem.length === 1 && deltaIndex <= reverseIndex) {
+          reverseIndex--;
+        }
+      }
+    }
+
+    return reverseIndex;
+  };
+
+  var collectChildrenReverseFilter = function collectChildrenReverseFilter(context) {
+    if (!context || !context.children) {
+      return;
+    }
+    if (context.delta._t !== 'a') {
+      return;
+    }
+    var length = context.children.length;
+    var child;
+    var delta = {
+      _t: 'a'
+    };
+
+    for (var index = 0; index < length; index++) {
+      child = context.children[index];
+      var name = child.newName;
+      if (typeof name === 'undefined') {
+        name = reverseArrayDeltaIndex(context.delta, child.childName, child.result);
+      }
+      if (delta[name] !== child.result) {
+        delta[name] = child.result;
+      }
+    }
+    context.setResult(delta).exit();
+  };
+  collectChildrenReverseFilter.filterName = 'arraysCollectChildren';
+
+  exports.diffFilter = diffFilter;
+  exports.patchFilter = patchFilter;
+  exports.collectChildrenPatchFilter = collectChildrenPatchFilter;
+  exports.reverseFilter = reverseFilter;
+  exports.collectChildrenReverseFilter = collectChildrenReverseFilter;
+
+  },{"../contexts/diff":5,"../contexts/patch":6,"../contexts/reverse":7,"./lcs":13}],12:[function(require,module,exports){
+  var diffFilter = function datesDiffFilter(context) {
+    if (context.left instanceof Date) {
+      if (context.right instanceof Date) {
+        if (context.left.getTime() !== context.right.getTime()) {
+          context.setResult([context.left, context.right]);
+        } else {
+          context.setResult(undefined);
+        }
+      } else {
+        context.setResult([context.left, context.right]);
+      }
+      context.exit();
+    } else if (context.right instanceof Date) {
+      context.setResult([context.left, context.right]).exit();
+    }
+  };
+  diffFilter.filterName = 'dates';
+
+  exports.diffFilter = diffFilter;
+
+  },{}],13:[function(require,module,exports){
+  /*
+
+  LCS implementation that supports arrays or strings
+
+  reference: http://en.wikipedia.org/wiki/Longest_common_subsequence_problem
+
+  */
+
+  var defaultMatch = function(array1, array2, index1, index2) {
+    return array1[index1] === array2[index2];
+  };
+
+  var lengthMatrix = function(array1, array2, match, context) {
+    var len1 = array1.length;
+    var len2 = array2.length;
+    var x, y;
+
+    // initialize empty matrix of len1+1 x len2+1
+    var matrix = [len1 + 1];
+    for (x = 0; x < len1 + 1; x++) {
+      matrix[x] = [len2 + 1];
+      for (y = 0; y < len2 + 1; y++) {
+        matrix[x][y] = 0;
+      }
+    }
+    matrix.match = match;
+    // save sequence lengths for each coordinate
+    for (x = 1; x < len1 + 1; x++) {
+      for (y = 1; y < len2 + 1; y++) {
+        if (match(array1, array2, x - 1, y - 1, context)) {
+          matrix[x][y] = matrix[x - 1][y - 1] + 1;
+        } else {
+          matrix[x][y] = Math.max(matrix[x - 1][y], matrix[x][y - 1]);
+        }
+      }
+    }
+    return matrix;
+  };
+
+  var backtrack = function(matrix, array1, array2, index1, index2, context) {
+    if (index1 === 0 || index2 === 0) {
+      return {
+        sequence: [],
+        indices1: [],
+        indices2: []
+      };
+    }
+
+    if (matrix.match(array1, array2, index1 - 1, index2 - 1, context)) {
+      var subsequence = backtrack(matrix, array1, array2, index1 - 1, index2 - 1, context);
+      subsequence.sequence.push(array1[index1 - 1]);
+      subsequence.indices1.push(index1 - 1);
+      subsequence.indices2.push(index2 - 1);
+      return subsequence;
+    }
+
+    if (matrix[index1][index2 - 1] > matrix[index1 - 1][index2]) {
+      return backtrack(matrix, array1, array2, index1, index2 - 1, context);
+    } else {
+      return backtrack(matrix, array1, array2, index1 - 1, index2, context);
+    }
+  };
+
+  var get = function(array1, array2, match, context) {
+    context = context || {};
+    var matrix = lengthMatrix(array1, array2, match || defaultMatch, context);
+    var result = backtrack(matrix, array1, array2, array1.length, array2.length, context);
+    if (typeof array1 === 'string' && typeof array2 === 'string') {
+      result.sequence = result.sequence.join('');
+    }
+    return result;
+  };
+
+  exports.get = get;
+
+  },{}],14:[function(require,module,exports){
+  var DiffContext = require('../contexts/diff').DiffContext;
+  var PatchContext = require('../contexts/patch').PatchContext;
+  var ReverseContext = require('../contexts/reverse').ReverseContext;
+
+  var collectChildrenDiffFilter = function collectChildrenDiffFilter(context) {
+    if (!context || !context.children) {
+      return;
+    }
+    var length = context.children.length;
+    var child;
+    var result = context.result;
+    for (var index = 0; index < length; index++) {
+      child = context.children[index];
+      if (typeof child.result === 'undefined') {
+        continue;
+      }
+      result = result || {};
+      result[child.childName] = child.result;
+    }
+    if (result && context.leftIsArray) {
+      result._t = 'a';
+    }
+    context.setResult(result).exit();
+  };
+  collectChildrenDiffFilter.filterName = 'collectChildren';
+
+  var objectsDiffFilter = function objectsDiffFilter(context) {
+    if (context.leftIsArray || context.leftType !== 'object') {
+      return;
+    }
+
+    var name, child, propertyFilter = context.options.propertyFilter;
+    for (name in context.left) {
+      if (!Object.prototype.hasOwnProperty.call(context.left, name)) {
+        continue;
+      }
+      if (propertyFilter && !propertyFilter(name, context)) {
+        continue;
+      }
+      child = new DiffContext(context.left[name], context.right[name]);
+      context.push(child, name);
+    }
+    for (name in context.right) {
+      if (!Object.prototype.hasOwnProperty.call(context.right, name)) {
+        continue;
+      }
+      if (propertyFilter && !propertyFilter(name, context)) {
+        continue;
+      }
+      if (typeof context.left[name] === 'undefined') {
+        child = new DiffContext(undefined, context.right[name]);
+        context.push(child, name);
+      }
+    }
+
+    if (!context.children || context.children.length === 0) {
+      context.setResult(undefined).exit();
+      return;
+    }
+    context.exit();
+  };
+  objectsDiffFilter.filterName = 'objects';
+
+  var patchFilter = function nestedPatchFilter(context) {
+    if (!context.nested) {
+      return;
+    }
+    if (context.delta._t) {
+      return;
+    }
+    var name, child;
+    for (name in context.delta) {
+      child = new PatchContext(context.left[name], context.delta[name]);
+      context.push(child, name);
+    }
+    context.exit();
+  };
+  patchFilter.filterName = 'objects';
+
+  var collectChildrenPatchFilter = function collectChildrenPatchFilter(context) {
+    if (!context || !context.children) {
+      return;
+    }
+    if (context.delta._t) {
+      return;
+    }
+    var length = context.children.length;
+    var child;
+    for (var index = 0; index < length; index++) {
+      child = context.children[index];
+      if (Object.prototype.hasOwnProperty.call(context.left, child.childName) && child.result === undefined) {
+        delete context.left[child.childName];
+      } else if (context.left[child.childName] !== child.result) {
+        context.left[child.childName] = child.result;
+      }
+    }
+    context.setResult(context.left).exit();
+  };
+  collectChildrenPatchFilter.filterName = 'collectChildren';
+
+  var reverseFilter = function nestedReverseFilter(context) {
+    if (!context.nested) {
+      return;
+    }
+    if (context.delta._t) {
+      return;
+    }
+    var name, child;
+    for (name in context.delta) {
+      child = new ReverseContext(context.delta[name]);
+      context.push(child, name);
+    }
+    context.exit();
+  };
+  reverseFilter.filterName = 'objects';
+
+  var collectChildrenReverseFilter = function collectChildrenReverseFilter(context) {
+    if (!context || !context.children) {
+      return;
+    }
+    if (context.delta._t) {
+      return;
+    }
+    var length = context.children.length;
+    var child;
+    var delta = {};
+    for (var index = 0; index < length; index++) {
+      child = context.children[index];
+      if (delta[child.childName] !== child.result) {
+        delta[child.childName] = child.result;
+      }
+    }
+    context.setResult(delta).exit();
+  };
+  collectChildrenReverseFilter.filterName = 'collectChildren';
+
+  exports.collectChildrenDiffFilter = collectChildrenDiffFilter;
+  exports.objectsDiffFilter = objectsDiffFilter;
+  exports.patchFilter = patchFilter;
+  exports.collectChildrenPatchFilter = collectChildrenPatchFilter;
+  exports.reverseFilter = reverseFilter;
+  exports.collectChildrenReverseFilter = collectChildrenReverseFilter;
+
+  },{"../contexts/diff":5,"../contexts/patch":6,"../contexts/reverse":7}],15:[function(require,module,exports){
+  /* global diff_match_patch */
+  var TEXT_DIFF = 2;
+  var DEFAULT_MIN_LENGTH = 60;
+  var cachedDiffPatch = null;
+
+  var getDiffMatchPatch = function(required) {
+    /*jshint camelcase: false */
+
+    if (!cachedDiffPatch) {
+      var instance;
+      if (typeof diff_match_patch !== 'undefined') {
+        // already loaded, probably a browser
+        instance = typeof diff_match_patch === 'function' ?
+          new diff_match_patch() : new diff_match_patch.diff_match_patch();
+      } else if (typeof require === 'function') {
+        try {
+          var dmpModuleName = 'diff_match_patch_uncompressed';
+          var dmp = require('../../public/external/' + dmpModuleName);
+          instance = new dmp.diff_match_patch();
+        } catch (err) {
+          instance = null;
+        }
+      }
+      if (!instance) {
+        if (!required) {
+          return null;
+        }
+        var error = new Error('text diff_match_patch library not found');
+        error.diff_match_patch_not_found = true;
+        throw error;
+      }
+      cachedDiffPatch = {
+        diff: function(txt1, txt2) {
+          return instance.patch_toText(instance.patch_make(txt1, txt2));
+        },
+        patch: function(txt1, patch) {
+          var results = instance.patch_apply(instance.patch_fromText(patch), txt1);
+          for (var i = 0; i < results[1].length; i++) {
+            if (!results[1][i]) {
+              var error = new Error('text patch failed');
+              error.textPatchFailed = true;
+            }
+          }
+          return results[0];
+        }
+      };
+    }
+    return cachedDiffPatch;
+  };
+
+  var diffFilter = function textsDiffFilter(context) {
+    if (context.leftType !== 'string') {
+      return;
+    }
+    var minLength = (context.options && context.options.textDiff &&
+      context.options.textDiff.minLength) || DEFAULT_MIN_LENGTH;
+    if (context.left.length < minLength ||
+      context.right.length < minLength) {
+      context.setResult([context.left, context.right]).exit();
+      return;
+    }
+    // large text, try to use a text-diff algorithm
+    var diffMatchPatch = getDiffMatchPatch();
+    if (!diffMatchPatch) {
+      // diff-match-patch library not available, fallback to regular string replace
+      context.setResult([context.left, context.right]).exit();
+      return;
+    }
+    var diff = diffMatchPatch.diff;
+    context.setResult([diff(context.left, context.right), 0, TEXT_DIFF]).exit();
+  };
+  diffFilter.filterName = 'texts';
+
+  var patchFilter = function textsPatchFilter(context) {
+    if (context.nested) {
+      return;
+    }
+    if (context.delta[2] !== TEXT_DIFF) {
+      return;
+    }
+
+    // text-diff, use a text-patch algorithm
+    var patch = getDiffMatchPatch(true).patch;
+    context.setResult(patch(context.left, context.delta[0])).exit();
+  };
+  patchFilter.filterName = 'texts';
+
+  var textDeltaReverse = function(delta) {
+    var i, l, lines, line, lineTmp, header = null,
+      headerRegex = /^@@ +\-(\d+),(\d+) +\+(\d+),(\d+) +@@$/,
+      lineHeader, lineAdd, lineRemove;
+    lines = delta.split('\n');
+    for (i = 0, l = lines.length; i < l; i++) {
+      line = lines[i];
+      var lineStart = line.slice(0, 1);
+      if (lineStart === '@') {
+        header = headerRegex.exec(line);
+        lineHeader = i;
+        lineAdd = null;
+        lineRemove = null;
+
+        // fix header
+        lines[lineHeader] = '@@ -' + header[3] + ',' + header[4] + ' +' + header[1] + ',' + header[2] + ' @@';
+      } else if (lineStart === '+') {
+        lineAdd = i;
+        lines[i] = '-' + lines[i].slice(1);
+        if (lines[i - 1].slice(0, 1) === '+') {
+          // swap lines to keep default order (-+)
+          lineTmp = lines[i];
+          lines[i] = lines[i - 1];
+          lines[i - 1] = lineTmp;
+        }
+      } else if (lineStart === '-') {
+        lineRemove = i;
+        lines[i] = '+' + lines[i].slice(1);
+      }
+    }
+    return lines.join('\n');
+  };
+
+  var reverseFilter = function textsReverseFilter(context) {
+    if (context.nested) {
+      return;
+    }
+    if (context.delta[2] !== TEXT_DIFF) {
+      return;
+    }
+
+    // text-diff, use a text-diff algorithm
+    context.setResult([textDeltaReverse(context.delta[0]), 0, TEXT_DIFF]).exit();
+  };
+  reverseFilter.filterName = 'texts';
+
+  exports.diffFilter = diffFilter;
+  exports.patchFilter = patchFilter;
+  exports.reverseFilter = reverseFilter;
+
+  },{}],16:[function(require,module,exports){
+  var isArray = (typeof Array.isArray === 'function') ?
+    // use native function
+    Array.isArray :
+    // use instanceof operator
+    function(a) {
+      return a instanceof Array;
+    };
+
+  var diffFilter = function trivialMatchesDiffFilter(context) {
+    if (context.left === context.right) {
+      context.setResult(undefined).exit();
+      return;
+    }
+    if (typeof context.left === 'undefined') {
+      if (typeof context.right === 'function') {
+        throw new Error('functions are not supported');
+      }
+      context.setResult([context.right]).exit();
+      return;
+    }
+    if (typeof context.right === 'undefined') {
+      context.setResult([context.left, 0, 0]).exit();
+      return;
+    }
+    if (typeof context.left === 'function' || typeof context.right === 'function') {
+      throw new Error('functions are not supported');
+    }
+    context.leftType = context.left === null ? 'null' : typeof context.left;
+    context.rightType = context.right === null ? 'null' : typeof context.right;
+    if (context.leftType !== context.rightType) {
+      context.setResult([context.left, context.right]).exit();
+      return;
+    }
+    if (context.leftType === 'boolean' || context.leftType === 'number') {
+      context.setResult([context.left, context.right]).exit();
+      return;
+    }
+    if (context.leftType === 'object') {
+      context.leftIsArray = isArray(context.left);
+    }
+    if (context.rightType === 'object') {
+      context.rightIsArray = isArray(context.right);
+    }
+    if (context.leftIsArray !== context.rightIsArray) {
+      context.setResult([context.left, context.right]).exit();
+      return;
+    }
+
+    if (context.left instanceof RegExp) {
+      if (context.right instanceof RegExp) {
+        context.setResult([context.left.toString(), context.right.toString()]).exit();
+      } else {
+        context.setResult([context.left, context.right]).exit();
+        return;
+      }
+    }
+  };
+  diffFilter.filterName = 'trivial';
+
+  var patchFilter = function trivialMatchesPatchFilter(context) {
+    if (typeof context.delta === 'undefined') {
+      context.setResult(context.left).exit();
+      return;
+    }
+    context.nested = !isArray(context.delta);
+    if (context.nested) {
+      return;
+    }
+    if (context.delta.length === 1) {
+      context.setResult(context.delta[0]).exit();
+      return;
+    }
+    if (context.delta.length === 2) {
+      if (context.left instanceof RegExp) {
+        var regexArgs = /^\/(.*)\/([gimyu]+)$/.exec(context.delta[1]);
+        if (regexArgs) {
+          context.setResult(new RegExp(regexArgs[1], regexArgs[2])).exit();
+          return;
+        }
+      }
+      context.setResult(context.delta[1]).exit();
+      return;
+    }
+    if (context.delta.length === 3 && context.delta[2] === 0) {
+      context.setResult(undefined).exit();
+      return;
+    }
+  };
+  patchFilter.filterName = 'trivial';
+
+  var reverseFilter = function trivialReferseFilter(context) {
+    if (typeof context.delta === 'undefined') {
+      context.setResult(context.delta).exit();
+      return;
+    }
+    context.nested = !isArray(context.delta);
+    if (context.nested) {
+      return;
+    }
+    if (context.delta.length === 1) {
+      context.setResult([context.delta[0], 0, 0]).exit();
+      return;
+    }
+    if (context.delta.length === 2) {
+      context.setResult([context.delta[1], context.delta[0]]).exit();
+      return;
+    }
+    if (context.delta.length === 3 && context.delta[2] === 0) {
+      context.setResult([context.delta[0]]).exit();
+      return;
+    }
+  };
+  reverseFilter.filterName = 'trivial';
+
+  exports.diffFilter = diffFilter;
+  exports.patchFilter = patchFilter;
+  exports.reverseFilter = reverseFilter;
+
+  },{}],17:[function(require,module,exports){
+
+  var environment = require('./environment');
+
+  var DiffPatcher = require('./diffpatcher').DiffPatcher;
+  exports.DiffPatcher = DiffPatcher;
+
+  exports.create = function(options){
+    return new DiffPatcher(options);
+  };
+
+  exports.dateReviver = require('./date-reviver');
+
+  var defaultInstance;
+
+  exports.diff = function() {
+    if (!defaultInstance) {
+      defaultInstance = new DiffPatcher();
+    }
+    return defaultInstance.diff.apply(defaultInstance, arguments);
+  };
+
+  exports.patch = function() {
+    if (!defaultInstance) {
+      defaultInstance = new DiffPatcher();
+    }
+    return defaultInstance.patch.apply(defaultInstance, arguments);
+  };
+
+  exports.unpatch = function() {
+    if (!defaultInstance) {
+      defaultInstance = new DiffPatcher();
+    }
+    return defaultInstance.unpatch.apply(defaultInstance, arguments);
+  };
+
+  exports.reverse = function() {
+    if (!defaultInstance) {
+      defaultInstance = new DiffPatcher();
+    }
+    return defaultInstance.reverse.apply(defaultInstance, arguments);
+  };
+
+  exports.clone = function() {
+    if (!defaultInstance) {
+      defaultInstance = new DiffPatcher();
+    }
+    return defaultInstance.clone.apply(defaultInstance, arguments);
+  };
+
+  exports.homepage = 'https://github.com/benjamine/jsondiffpatch';
+  exports.version = '0.2.4';
+
+  var formatterModuleName = './formatters';
+  var formatters = require(formatterModuleName);
+  exports.formatters = formatters;
+  },{"./date-reviver":8,"./diffpatcher":9,"./environment":10}],18:[function(require,module,exports){
+  var Pipe = function Pipe(name) {
+    this.name = name;
+    this.filters = [];
+  };
+
+  Pipe.prototype.process = function(input) {
+    if (!this.processor) {
+      throw new Error('add this pipe to a processor before using it');
+    }
+    var debug = this.debug;
+    var length = this.filters.length;
+    var context = input;
+    for (var index = 0; index < length; index++) {
+      var filter = this.filters[index];
+      if (debug) {
+        this.log('filter: ' + filter.filterName);
+      }
+      filter(context);
+      if (typeof context === 'object' && context.exiting) {
+        context.exiting = false;
+        break;
+      }
+    }
+    if (!context.next && this.resultCheck) {
+      this.resultCheck(context);
+    }
+  };
+
+  Pipe.prototype.log = function(msg) {
+    console.log('[jsondiffpatch] ' + this.name + ' pipe, ' + msg);
+  };
+
+  Pipe.prototype.append = function() {
+    this.filters.push.apply(this.filters, arguments);
+    return this;
+  };
+
+  Pipe.prototype.prepend = function() {
+    this.filters.unshift.apply(this.filters, arguments);
+    return this;
+  };
+
+  Pipe.prototype.indexOf = function(filterName) {
+    if (!filterName) {
+      throw new Error('a filter name is required');
+    }
+    for (var index = 0; index < this.filters.length; index++) {
+      var filter = this.filters[index];
+      if (filter.filterName === filterName) {
+        return index;
+      }
+    }
+    throw new Error('filter not found: ' + filterName);
+  };
+
+  Pipe.prototype.list = function() {
+    var names = [];
+    for (var index = 0; index < this.filters.length; index++) {
+      var filter = this.filters[index];
+      names.push(filter.filterName);
+    }
+    return names;
+  };
+
+  Pipe.prototype.after = function(filterName) {
+    var index = this.indexOf(filterName);
+    var params = Array.prototype.slice.call(arguments, 1);
+    if (!params.length) {
+      throw new Error('a filter is required');
+    }
+    params.unshift(index + 1, 0);
+    Array.prototype.splice.apply(this.filters, params);
+    return this;
+  };
+
+  Pipe.prototype.before = function(filterName) {
+    var index = this.indexOf(filterName);
+    var params = Array.prototype.slice.call(arguments, 1);
+    if (!params.length) {
+      throw new Error('a filter is required');
+    }
+    params.unshift(index, 0);
+    Array.prototype.splice.apply(this.filters, params);
+    return this;
+  };
+
+  Pipe.prototype.clear = function() {
+    this.filters.length = 0;
+    return this;
+  };
+
+  Pipe.prototype.shouldHaveResult = function(should) {
+    if (should === false) {
+      this.resultCheck = null;
+      return;
+    }
+    if (this.resultCheck) {
+      return;
+    }
+    var pipe = this;
+    this.resultCheck = function(context) {
+      if (!context.hasResult) {
+        console.log(context);
+        var error = new Error(pipe.name + ' failed');
+        error.noResult = true;
+        throw error;
+      }
+    };
+    return this;
+  };
+
+  exports.Pipe = Pipe;
+
+  },{}],19:[function(require,module,exports){
+
+  var Processor = function Processor(options){
+    this.selfOptions = options || {};
+    this.pipes = {};
+  };
+
+  Processor.prototype.options = function(options) {
+    if (options) {
+      this.selfOptions = options;
+    }
+    return this.selfOptions;
+  };
+
+  Processor.prototype.pipe = function(name, pipe) {
+    if (typeof name === 'string') {
+      if (typeof pipe === 'undefined') {
+        return this.pipes[name];
+      } else {
+        this.pipes[name] = pipe;
+      }
+    }
+    if (name && name.name) {
+      pipe = name;
+      if (pipe.processor === this) { return pipe; }
+      this.pipes[pipe.name] = pipe;
+    }
+    pipe.processor = this;
+    return pipe;
+  };
+
+  Processor.prototype.process = function(input, pipe) {
+    var context = input;
+    context.options = this.options();
+    var nextPipe = pipe || input.pipe || 'default';
+    var lastPipe, lastContext;
+    while (nextPipe) {
+      if (typeof context.nextAfterChildren !== 'undefined') {
+        // children processed and coming back to parent
+        context.next = context.nextAfterChildren;
+        context.nextAfterChildren = null;
+      }
+
+      if (typeof nextPipe === 'string') {
+        nextPipe = this.pipe(nextPipe);
+      }
+      nextPipe.process(context);
+      lastContext = context;
+      lastPipe = nextPipe;
+      nextPipe = null;
+      if (context) {
+        if (context.next) {
+          context = context.next;
+          nextPipe = lastContext.nextPipe || context.pipe || lastPipe;
+        }
+      }
+    }
+    return context.hasResult ? context.result : undefined;
+  };
+
+  exports.Processor = Processor;
+
+  },{}]},{},[1])(1)
+  });
new file mode 100644
--- /dev/null
+++ b/devtools/client/shared/vendor/jsondiffpatch/moz.build
@@ -0,0 +1,11 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DevToolsModules(
+    'formatter-json.js',
+    'formatters.js',
+    'jsondiffpatch-full.js',
+)
--- a/devtools/client/shared/vendor/moz.build
+++ b/devtools/client/shared/vendor/moz.build
@@ -1,16 +1,17 @@
 # -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
 # vim: set filetype=python:
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 DIRS += [
     'stringvalidator',
+    'jsondiffpatch',
 ]
 
 modules = []
 modules += [
     'immutable.js',
     'jsol.js',
     'jszip.js',
     'lodash.js',
--- a/devtools/shared/mixinService.js
+++ b/devtools/shared/mixinService.js
@@ -4,87 +4,103 @@
 /* globals Services */
 
 "use strict";
 
 const { Cu } = require("chrome");
 const { Services } = Cu.import("resource://gre/modules/Services.jsm", {});
 const lodash = require("devtools/client/shared/vendor/lodash");
 
+const jsondiffpatch =
+  require("devtools/client/shared/vendor/jsondiffpatch/jsondiffpatch-full");
+const formatterJSON =
+  require("devtools/client/shared/vendor/jsondiffpatch/formatter-json");
+
+const objectDiffFilter =
+  Services.prefs.getStringPref("devtools.performance.measure.objectdiff.filter");
 const whyDidYouUpdateFilter =
   Services.prefs.getStringPref("devtools.performance.measure.whydidyouupdate.filter");
 
 const MATCH_OPERATORS_REGEX = /[|\\{}()[\]^$+*?.]/g;
 
 class MixinService {
   constructor() {
+    this.objectDiffEnabled =
+      Services.prefs.getBoolPref("devtools.performance.measure.objectdiff");
     this.whyDidYouUpdateEnabled =
       Services.prefs.getBoolPref("devtools.performance.measure.whydidyouupdate");
   }
 
   get mixins() {
     let _mixins = [];
 
+    if (this.objectDiffEnabled) {
+      _mixins.push(ObjectDiffMixin);
+    }
+
     if (this.whyDidYouUpdateEnabled) {
       _mixins.push(WhyDidYouUpdateMixin);
     }
 
     return _mixins;
   }
 }
 
 const WhyDidYouUpdateMixin = {
   componentDidUpdate(prevProps, prevState) {
-    this.deepDiff({props: prevProps, state: prevState},
+    this.deepDiff_WhyDidYouUpdate({props: prevProps, state: prevState},
                   {props: this.props, state: this.state},
                   this.constructor.displayName);
   },
 
-  isRequiredUpdateObject(o) {
+  // eslint-disable-next-line
+  isRequiredUpdateObject_WhyDidYouUpdate(o) {
     return Array.isArray(o) || (o && o.constructor === Object.prototype.constructor);
   },
 
-  deepDiff(prev, next, name) {
-    if (!this.shouldIncludeComponent()) {
+  // eslint-disable-next-line
+  deepDiff_WhyDidYouUpdate(prev, next, name) {
+    if (!this.shouldIncludeComponent_WhyDidYouUpdate()) {
       return;
     }
 
     const notify = (status) => {
       console.warn(status);
       console.log("before ", prev);
       console.log("after ", next);
     };
 
     if (!lodash.isEqual(prev, next)) {
       console.group(name);
       if ([prev, next].every(lodash.isFunction)) {
         notify("Value is a function. Possible avoidable re-render?");
-      } else if (![prev, next].every(this.isRequiredUpdateObject)) {
+      } else if (![prev, next].every(this.isRequiredUpdateObject_WhyDidYouUpdate)) {
         notify("Unavoidable re-render.");
       } else {
         const allKeys = lodash.union(lodash.keys(prev), lodash.keys(next));
         for (const currKey of allKeys) {
-          this.deepDiff(prev[currKey], next[currKey], currKey);
+          this.deepDiff_WhyDidYouUpdate(prev[currKey], next[currKey], currKey);
         }
       }
       console.groupEnd();
     } else if (prev !== next) {
       console.group(name);
       notify("Value did not change. Avoidable re-render!");
       if (lodash.isObject(prev) && lodash.isObject(next)) {
         const allKeys = lodash.union(lodash.keys(prev), lodash.keys(next));
         for (const currKey of allKeys) {
-          this.deepDiff(prev[currKey], next[currKey], currKey);
+          this.deepDiff_WhyDidYouUpdate(prev[currKey], next[currKey], currKey);
         }
       }
       console.groupEnd();
     }
   },
 
-  shouldIncludeComponent() {
+  // eslint-disable-next-line
+  shouldIncludeComponent_WhyDidYouUpdate() {
     let filter = whyDidYouUpdateFilter;
 
     if (!filter) {
       return true;
     }
 
     let name = this.constructor.displayName;
 
@@ -102,14 +118,64 @@ const WhyDidYouUpdateMixin = {
       }
     }
 
     // Check for a string match.
     return name === filter;
   }
 };
 
+const ObjectDiffMixin = {
+  componentDidUpdate(prevProps, prevState) {
+    this.deepDiff_ObjectDiff({props: prevProps, state: prevState},
+                             {props: this.props, state: this.state},
+                             this.constructor.displayName);
+  },
+
+  // eslint-disable-next-line
+  deepDiff_ObjectDiff(prev, next, name) {
+    if (!this.shouldIncludeComponent_ObjectDiff()) {
+      return;
+    }
+
+    let delta = jsondiffpatch.diff(prev, next);
+    let result = formatterJSON.format(delta, prev);
+
+    if (result) {
+      console.log(name, result);
+    }
+  },
+
+  // eslint-disable-next-line
+  shouldIncludeComponent_ObjectDiff() {
+    let filter = objectDiffFilter;
+
+    if (!filter) {
+      return true;
+    }
+
+    let name = this.constructor.displayName;
+
+    // First check for a regular expression.
+    if (filter.startsWith("/") && filter.endsWith("/")) {
+      filter = filter.substr(1, filter.length - 2);
+
+      let pattern = filter.replace(MATCH_OPERATORS_REGEX, "\\$&");
+
+      try {
+        let rx = new RegExp(pattern);
+        return rx.test(name);
+      } catch (e) {
+        // Do nothing
+      }
+    }
+
+    // Check for a string match.
+    return name === filter;
+  }
+};
+
 // Make this.mixinService a singleton.
 if (!this.mixinService) {
   this.mixinService = new MixinService();
 }
 
 exports.mixinService = this.mixinService;
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -1067,16 +1067,18 @@ pref("devtools.defaultColorUnit", "autho
 pref("devtools.dump.emit", false);
 
 // Controls whether EventEmitter module throws dump message on each emit
 pref("toolkit.dump.emit", false);
 
 // Performance measurement options
 pref("devtools.performance.measure.whydidyouupdate", false);
 pref("devtools.performance.measure.whydidyouupdate.filter", "");
+pref("devtools.performance.measure.objectdiff", false);
+pref("devtools.performance.measure.objectdiff.filter", "");
 
 // Disable device discovery logging
 pref("devtools.discovery.log", false);
 // Whether to scan for DevTools devices via WiFi
 pref("devtools.remote.wifi.scan", true);
 // Whether UI options for controlling device visibility over WiFi are shown
 // N.B.: This does not set whether the device can be discovered via WiFi, only
 // whether the UI control to make such a choice is shown to the user
--- a/toolkit/content/license.html
+++ b/toolkit/content/license.html
@@ -121,16 +121,18 @@
       <li><a href="about:license#libevent">libevent License</a></li>
       <li><a href="about:license#libffi">libffi License</a></li>
       <li><a href="about:license#libjingle">libjingle License</a></li>
       <li><a href="about:license#libnestegg">libnestegg License</a></li>
       <li><a href="about:license#libsoundtouch">libsoundtouch License</a></li>
       <li><a href="about:license#libyuv">libyuv License</a></li>
       <li><a href="about:license#hunspell-lt">Lithuanian Spellchecking Dictionary License</a></li>
       <li><a href="about:license#lodash">lodash License</a></li>
+      <li><a href="about:license#google-diff-match-patch">google-diff-match-patch License</a></li>
+      <li><a href="about:license#jsondiffpatch">jsondiffpatch License</a></li>
       <li><a href="about:license#matches">matches License</a></li>
       <li><a href="about:license#microformatsshiv">MIT license — microformat-shiv</a></li>
       <li><a href="about:license#myspell">MySpell License</a></li>
       <li><a href="about:license#naturalSort">naturalSort License</a></li>
       <li><a href="about:license#nicer">nICEr License</a></li>
       <li><a href="about:license#node-md5">node-md5 License</a></li>
       <li><a href="about:license#node-properties">node-properties License</a></li>
       <li><a href="about:license#nom">nom License</a></li>
@@ -4507,17 +4509,72 @@ CC0: http://creativecommons.org/publicdo
 Files located in the node_modules and vendor directories are externally
 maintained libraries used by this software which have their own
 licenses; we recommend you read them, as their terms may differ from the
 terms above.
 
 </pre>
 
 
-    <hr>
+<hr>
+
+    <h1><a id="google-diff-match-patch"></a>License - google-diff-match-patch</h1>
+
+    <p>This license applies to some of the code in
+    <code>devtools/client/shared/vendor/jsondiffpatch/jsondiffpatch-full.js</code>.</p>
+
+<pre>
+Copyright 2006 Google Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+</pre>
+
+<hr>
+
+    <h1><a id="jsondiffpatch"></a>License - jsondiffpatch</h1>
+
+    <p>This license applies to some of the code in
+    <code>devtools/client/shared/vendor/jsondiffpatch/jsondiffpatch-full.js</code>.</p>
+
+<pre>
+The MIT License
+
+Copyright (c) 2014 Benjamín Eidelman twitter.com/beneidel
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+</pre>
+
+<hr>
 
     <h1><a id="matches"></a>matches License</h1>
 
     <p>This license applies to files in the directory
     <code>third_party/rust/matches</code>.</p>
 
 <pre>
 Copyright (c) 2014-2016 Simon Sapin